Plasma spray systems and methods

Abstract

Plasma spraying systems comprise multiple zones, wherein the energy required for different processes within the system can be independently controlled. In some embodiments, a plasma spraying system includes a first zone in which an ionic substance is generated from a target material using a first energy input, and the ionic substance binds in the first zone to form a plurality of microparticles, or to form a coating on a plurality of input microparticles input to the first zone. The plasma spraying system may further include a second zone comprising a chamber coupled to a microwave energy source, the microwave energy source ionizing the plurality of microparticles to form a plurality of ionized microparticles and forming a plasma jet. The plasma spraying system may further include a third zone comprising an electric field to accelerate the plurality of ionized microparticles and form a plasma coating.

Description

Plasma Spray Systems and Methods Related Applications This application claims the benefit of U.S. Non - provisional Patent Application No. 16 / 460,177, filed on July 2, 2019, and titled "Plasma Spray Systems and Methods", which claims the priority of U.S. Provisional Patent Application No. 62 / 714,030, filed on August 2, 2018, and titled "Plasma Spray Deposition"; and U.S. Provisional Patent Application No. 62 / 720,677, filed on August 21, 2018, and titled "Plasma Spray Systems and Methods"; the entire disclosures of these applications are incorporated herein by reference for all purposes. The present invention relates to plasma spray systems and methods. Background Art The plasma spray process - also known as thermal spraying - is used to deposit materials onto a surface by introducing a feedstock material into a plasma jet output from a plasma torch. Thermal spraying can provide thick coatings (e.g., in a thickness range of 20 microns to several millimeters depending on the process and feedstock) at high deposition rates over large areas compared to other coating processes such as electroplating, physical and chemical vapor deposition. Feedstock materials that can be used for thermal spraying include metals, alloys, ceramics, plastics, and composites, and can be in the form of powders, liquids, suspensions, or in some cases wires. The feedstock material is heated either electrically (plasma or arc) or chemically (combustion flame). Since the temperature in the plasma jet is typically about 5,000 - 8,000 K or higher as far as possible defined temperatures are concerned, the feedstock material can be heated, partially or completely melted or sublimated, or partially or completely evaporated, depending on the plasma pressure, the properties of the feedstock material (including the size of the feedstock material or particles), and the residence time of the feedstock material as it is propelled towards the substrate by the plasma jet. Upon hitting the substrate, in the case of a completely or partially melted material, the melted material flattens and rapidly solidifies to form a layer of deposited material on the substrate. Thus, in this case, the material deposited by plasma spraying typically consists of a large number of flakes formed by the flattening of the melted material on the substrate. Conventional plasma spray processes typically produce coatings with a large number of structural defects (such as voids, cracks, and delamination regions) between the flakes. Therefore, plasma spray deposited layers tend to have significantly different properties from bulk materials with similar compositions, such as lower mechanical strength and modulus of elasticity, lower thermal conductivity, and lower electrical conductivity. Summary of the Invention In some embodiments, a plasma spraying system includes a first zone that includes a target material and a device having a power source, where the power source is configured to generate a plurality of ionic species from the target material using energy from the power source; and the ionic species combine to form a plurality of microparticles. The plasma spraying system may further include a second zone connected to an output of the first zone, the second zone including a chamber coupled to a microwave energy source. In the second zone, the microwave energy source may supply microwave energy to the chamber to ionize the plurality of microparticles to form a plurality of ionized microparticles, and may generate a plasma jet including the plurality of ionized microparticles. The plasma spraying system may further include a third zone connected to an output of the second zone, the third zone including an electric field, where the plurality of ionized microparticles may be accelerated by the electric field to form a plasma spray including the ionized microparticles. In some embodiments, a plasma spraying system includes a first zone that includes: an inlet where a plurality of input microparticles are input into the first zone; a target material; and a device having a power source, where the power source is configured to generate a plurality of ionic species from the target material using energy from the power source, and the ionic species combine to form a coating on the plurality of input microparticles to form a plurality of coated microparticles. The plasma spraying system may further include a second zone connected to an output of the first zone, the second zone including a chamber coupled to a microwave energy source. In the second zone, the microwave energy source may supply microwave energy to the chamber to ionize the plurality of coated microparticles to form a plurality of ionized microparticles, and may generate a plasma jet including the plurality of ionized microparticles. The plasma spraying system may further include a third zone connected to an output of the second zone, the third zone including an electric field, where the plurality of ionized microparticles may be accelerated by the electric field to form a plasma spray including the ionized microparticles. In some embodiments, a method includes providing a plasma spraying system that includes: a first zone that includes a target material and a device having a power source; a second zone connected to an output of the first zone, the second zone including a chamber coupled to a microwave energy source; and a third zone connected to an output of the second zone, the third zone including an electric field. The method may further include: generating a plurality of ionic species from the target material using energy from the power source in the first zone; combining the ionic species to form a plurality of microparticles in the first zone; supplying microwave energy to the chamber using the microwave energy source to ionize the plurality of microparticles and form a plurality of ionized microparticles in the second zone; generating a plasma jet including the plurality of ionized microparticles in the second zone; and accelerating the plurality of ionized microparticles using the electric field to form a plasma spray including the plurality of ionized microparticles in the third zone. In some embodiments, a method includes providing a plasma spraying system that includes: a first zone that includes an inlet where a plurality of input particles are input into the first zone, a target material, and a device having a power source; a second zone connected to an output of the first zone, the second zone including a chamber coupled to a microwave energy source; and a third zone connected to an output of the second zone, the third zone including an electric field. The method may further include: using energy from the power source in the first zone to generate a plurality of ionic species from the target material; combining the ionic species in the first zone to form a coating on the plurality of input particles to form a plurality of coated particles; using the microwave energy source in the second zone to supply microwave energy to the chamber to ionize the plurality of coated particles and form a plurality of ionized particles; generating a plasma jet including the plurality of ionized particles in the second zone; and using the electric field in the third zone to accelerate the plurality of ionized particles to form a plasma spray including the plurality of ionized particles. Detailed Description of the Invention This embodiment discloses a plasma spraying system and method in which a plasma jet containing a single-component or multi-component material is generated. In some embodiments, the material from the plasma spraying system is collected as particles, while in other embodiments, the material is deposited (or coated) as a thin film onto a substrate. This plasma spraying system may be referred to as a "plasma torch" and / or a "plasma spray deposition system" (when referring to a system capable of depositing a thin film). The material within this plasma jet can form a high-quality coating on a substrate or can form unique particles that are collected. The formed particles and / or thin films can have novel properties such as, but not limited to, atomic structure (e.g., a specific carbon allotrope, or the bonding characteristics between carbon and a metal), morphology (e.g., porosity, microstructure, and in some cases particle shape), and / or other properties (e.g., surface area, purity, conductivity, etc.). A plasma spraying system including multiple zones is described, where the energy required for different processes within the system can be independently controlled. In some embodiments, the plasma spraying system includes three zones. In such embodiments, the first zone forms or modifies the particulates, the second zone ionizes the particulates and forms a plasma jet, and the third zone accelerates the ionized particulates. The processes occurring in the three zones require different energy inputs, and the multiple zones of the present plasma spraying system enable independent control of the energy required for each process. In some embodiments, the accelerated particulates are then deposited as a thin film on a substrate. In some embodiments, modifying the particulates in the first zone includes coating the particulates with a coating material. In the present system and method, these coatings can completely cover the particulates, partially cover the particulates, or decorate the particulates. In some embodiments, the resulting coatings can also penetrate into the particulates (e.g., deposit in pores within the input particulates). In other embodiments, the particulates collected from the output of the plasma spraying system are either used or fed as input to different downstream systems. In some cases, the plasma spraying system also has a zone for particulate collection in addition to two or three processing zones, where the first processing zone forms or modifies the particulates, the second processing zone ionizes the particulates and forms a plasma jet, an optional third processing zone accelerates the ionized particulates, and the collection zone coagulates the particulates from the plasma jet and outputs the formed particulates to a particulate collection system. In some embodiments, the particulates (or coated particulates) from the plasma spraying system are collected and subsequent downstream processing is performed. Some non-limiting examples of downstream processing include particulate size reduction (e.g., by mechanical grinding), and / or methods of increasing the material aggregation density (e.g., depositing a second material to fill voids) and their resulting electrical properties (e.g., improving the overall electrical network connection conductivity). An example of depositing a second material to fill voids is depositing a carbon layer onto porous carbon particulates to increase the density of the carbon particulates. In some embodiments, after downstream processing, the particulates can be deposited on a substrate to form a coating (e.g., using a wet coating method, or a separate plasma spraying system). Further description and examples of particulate collection systems and methods that can be used in conjunction with the present plasma spraying system are described in U.S. Patent No. 10,308,512, titled "Microwave Reactor System with Gas-Solids Separation", which is assigned to the same assignee as the present application and is incorporated herein by reference in its entirety for all purposes as if fully set forth herein. The plasma spraying systems and methods described herein are capable of producing and / or processing many different types of materials, including but not limited to metals, oxides, nitrides, carbon allotropes, charge storage materials, semiconductors, dielectrics, and magnetic materials. Accordingly, the materials for the input particles, input gases and / or liquids, and the formed particles and / or coatings in the first stage are not particularly limited. In some embodiments, the present plasma spraying system can produce a wide variety of materials with improved properties (e.g., higher quality or other unique properties) described herein by taking advantage of the versatility of plasma processing (e.g., using microwave energy) and through the integration of multiple material forming and / or coating regions (e.g., physical vapor deposition or sputtering regions) within the plasma spraying system as compared to conventional systems. Additionally, in some embodiments, the further integration of the acceleration region within the plasma spraying system results in films having improved properties (e.g., lower porosity, and / or better adhesion) as compared to conventional systems. In some embodiments, input particles are introduced into the plasma spraying system and the input particles are coated and / or modified prior to forming the ionized plasma jet. In some embodiments, input particles are introduced into the plasma spraying system and the produced particles are generated within the plasma spraying system, and both the input and produced particles are coated and / or modified prior to forming the ionized plasma jet. Some examples of particles that can be formed by the present plasma spraying system and / or input particles that can be introduced into the present plasma spraying system are carbon allotropes, silicon, carbon, aluminum, ceramics (e.g., FeSi, SiO x ). The particles produced or introduced are not particularly limited, and many different materials can be processed using the systems and methods described herein. In some non-limiting examples, materials with high permeability (e.g., nickel-iron soft ferromagnetic alloy), high relative permittivity (e.g., high-k dielectric materials such as perovskite), and / or high conductivity (e.g., metals) can be formed and / or coated to produce materials or specialty materials for many different applications. In some non-limiting examples, the particles generated and / or input that can be processed using the present system and method contain carbon allotropes and are described in U.S. Patent No. 9,997,334 titled "Seedless Particles with Carbon Allotropes" and U.S. Patent No. 9,862,606 titled "Carbon Allotropes", which are assigned to the same assignee as the present application and are incorporated herein by reference for all purposes as if fully set forth herein. In some embodiments, the carbon particles that can be processed by the systems and methods described herein include a plurality of carbon aggregates, each carbon aggregate having a plurality of carbon nanoparticles, each carbon nanoparticle including graphene, without seed (i.e., nucleation or core) particles. The graphene in the graphene-based carbon material can have up to 15 layers. The ratio, percentage, or fraction of carbon in the carbon aggregate to other elements other than hydrogen can be greater than 99%, or greater than 99.5%, or greater than 99.7%, or greater than 99.9%, or greater than 99.95%. The above "other elements other than hydrogen" can include any element that is not carbon or hydrogen, such as but not limited to metals, halogens, and / or oxygen. Medium-sized carbon aggregates can range from 1 to 50 microns, or from 1 micron to 50 microns, or from 2 microns to 20 microns, or from 5 microns to 40 microns, or from 5 microns to 30 microns, or from 10 microns to 30 microns, or from 10 microns to 25 microns, or from 10 microns to 20 microns. In some embodiments, the size distribution of the carbon aggregates ranges from 1 micron to 10 microns, or from 1 micron to 5 microns, or from 2 microns to 6 microns, or from 2 microns to 5 microns with 10%. The surface area of the carbon aggregate can be at least 50 m 2 / g, or from 50 to 3000 m 2 / g, or from 100 to 3000 m 2 / g, or from 50 to 2000 m 2 / g, or from 50 to 1500 m 2 / g, or from 50 to 1000 m 2 / g, or from 50 to 500 m 2 / g, or from 50 to 300 m 2 / g. The conductivity of the carbon aggregates upon compression can be greater than 500 S / m, or greater than 1000 S / m, or greater than 2000 S / m, or from 500 S / m to 20,000 S / m, or from 500 S / m to 10,000 S / m, or from 500 S / m to 5000 S / m, or from 500 S / m to 4000 S / m, or from 500 S / m to 3000 S / m, or from 2000 S / m to 5000 S / m, or from 2000 S / m to 4000 S / m, or from 1000 S / m to 5000 S / m, or from 1000 S / m to 3000 S / m. In some embodiments, particulates are generated and / or introduced into the system in the first zone, and these particulates are modified (e.g., coated or decorated). Some examples of particulates that can be generated and / or introduced into the system in the first zone and modified are carbon allotropes, silicon, carbon, aluminum, ceramics (e.g., FeSi, SiO x ). Many different materials can be coated on the particulates generated and / or introduced in the first zone, such as but not limited to carbon, sulfur, silicon, iron, nickel, manganese, metal oxides (e.g., ZnO, SiO, and NiO), metal carbides (e.g., SiC and AlC), metal silicides (e.g., FeSi), metal borides, metal nitrides (SiN), and many other types of ceramic materials. In some embodiments, a gas (or in some cases a gas and / or a liquid) is introduced into the system and particulates are formed and / or coated in the first zone from a target material and / or from the input gas (or in some cases the input gas and / or liquid). For example, the gas and / or liquid that can be introduced into the system for carbon particulate formation and / or for coating the input particulates with carbon are methane, ethane, methylacetylene-propadiene propane (MAPP), hexane, and ethanol. In other non-limiting examples, the generated particulates and / or the coating on the particulates can be formed and / or deposited from a mixed material such as trimethylamine (TMA), trimethylglycine (TMG), and tetraethyl orthosilicate (TEOS). Some examples of particulates that can be formed from a target material in the first zone are phase carbon, silicon carbide, metal oxides, metal nitrides, or metals. In some cases, the input particulates (i.e., those introduced into the plasma spraying system) are metals, and a compound film (e.g., a metal oxide or a metal nitride) is coated on the metal input particulates. In other cases, the input particulates contain a compound material, and a metal coating is deposited on the input particulates. Some examples of particulates that can be formed from the input gas (or in some cases the input gas and / or liquid) in the first zone are carbon allotropes (e.g., natural carbon), silicon, ZnO, AlO x and NiO. In some embodiments, a first zone in a plasma spray system includes a target material and a device having a power source, where the power source is configured to generate a plurality of ionic species from the target material and the ionic species combine to form a plurality of microparticles. The power source can be an AC, DC, RF, or high-power pulsed magnetron sputtering (HIPIMS) power source and can be configured to generate a plurality of ionic species from the target material by tuning the power, voltage, frequency, repetition rate, and / or other characteristics of the power source. The power source can be used to generate ionic species from the target material via any process, such as one or more of physical vapor deposition (PVD), thermal evaporation, sputtering, and pulsed laser deposition. In some embodiments, as described above, a gas (or in some cases an input gas and / or liquid) is introduced into the first zone in the plasma spray system to generate and / or coat microparticles, and additionally, the first zone includes a target material and a power source. In such embodiments, the ionic species generated from the target material can form additional microparticles in the first zone and / or coat the microparticles generated in the first zone from the input gas and / or liquid. In some embodiments, a plurality of microparticles are introduced into the first zone, and the first zone includes a target material and a power source. In this case, the power source can be used to generate a plurality of ionic species from the target material and the ionic species can combine to form a coating on the plurality of input microparticles to form a plurality of coated microparticles. In this case, the power source can be used to generate ionic species from the target material via any process, such as one or more of physical vapor deposition (PVD), thermal evaporation, sputtering, and pulsed laser deposition. As described above, many materials can be formed from such ionic species, including but not limited to carbon, sulfur, silicon, iron, nickel, manganese, metal oxides (e.g., ZnO, SiO, and NiO), metal carbides (e.g., SiC and AlC), metal silicides (e.g., FeSi), metal borides, metal nitrides (SiN), and many other types of conductive materials and / or ceramic materials. In other embodiments, the first zone forms microparticles or coats input microparticles using methods that do not require a target material, such as chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD). In such methods, the input gas is converted (e.g., dissociated) into microparticles formed in a reaction zone in the first zone, or into a coating on the input microparticles. As described above, many materials can be formed from such ionic species, including but not limited to carbon, sulfur, silicon, iron, nickel, manganese, metal oxides (e.g., ZnO, SiO, and NiO), metal carbides (e.g., SiC and AlC), metal silicides (e.g., FeSi), metal borides, metal nitrides (SiN), and many other types of conductive materials and / or ceramic materials. In some embodiments, the first zone contains more than one sub-zone. For example, particles can be input into the first zone, and the first zone contains more than one sub-zone to coat the input particles with more than one type of coating. In another example, particles are formed in a first sub-zone of the first zone (e.g., from a target material), and subsequent sub-zones coat the formed particles with one or more layers of coating. In some embodiments, the second zone includes a chamber coupled to a microwave energy source, where the microwave energy source supplies microwave energy to the chamber to ionize a plurality of particles (or coated particles) generated and / or modified in the first zone to form a plurality of ionized particles. Microwave plasmas are advantageous because the ionization efficiency of the particles (or coated particles) will be increased compared to other types of plasmas (e.g., a first-stage plasma for material formation). Although the fraction of ionized particles will be higher than that of the first stage, not all particles will be fully ionized in the second stage. A plasma jet containing a plurality of ionized particles can also be generated in the second zone. High-energy ionized particles that form the plasma jet output from the second zone can be formed using only the microwave energy coupled to the chamber or by adding additional energy (e.g., using an additional electric or magnetic field from an electrode or magnet) to the particles in the chamber. In some embodiments, a separate energy source will be used to add energy to the plasma jet (e.g., at a nozzle at the end of the second stage / zone) to include another stage of ionization before the material exits the second zone (or the torch). In some embodiments, the microwave energy is coupled between the microwave energy source and the chamber in the second zone using coaxial feed coupling, coupling for energy propagation in the transverse electric (TE) mode, coupling for energy propagation in the transverse magnetic (TM) mode, or coupling for energy propagation in the transverse electromagnetic (TEM) mode. In some embodiments, a microwave-assisted filament method is used to generate a microwave plasma in the second zone by coupling for energy propagation in the TEM mode. Using microwave plasma in the second zone of the present plasma spraying system to ionize the microparticles is beneficial compared to typical plasmas used in plasma torches (e.g., inductively coupled plasma, capacitively coupled plasma, or plasma formed using a discharge plate). This is because the microwave plasma having an energy in the range of about 1 eV to about 20 eV is a plasma with lower energy than the typical plasma torch plasmas having an energy of about 100 eV and higher (i.e., "soft" plasma). The lower energy of these soft plasmas enables the microparticles to be effectively ionized (i.e., a high fraction of the microparticles are sufficiently charged to be accelerated) without damaging and / or melting the microparticles. Since the microparticle morphology is kept intact, utilizing microwave plasma in the second zone enables the plasma spraying system to form microparticles and deposit thin films having unique morphologies. Using microwaves to form the plasma also improves the power consumption efficiency of the system because the energy can be more effectively coupled to the plasma compared to other types of plasmas. In some embodiments, greater than 90%, or greater than 95%, or greater than 98% of the microwave energy is coupled to the microwave plasma in the present plasma spraying system. Further descriptions and examples of systems and methods for forming beneficial low-energy microwave plasmas that can be combined with the present plasma spraying system are described in U.S. Patent No. 9,812,295 titled "Microwave Chemical Processing" or U.S. Patent No. 9,767,992 titled "Microwave Chemical Processing Reactor", which are assigned to the same assignee as the present application and are incorporated herein by reference for all purposes as if fully set forth herein. In some embodiments of the present plasma spraying system, the first zone is connected to the second zone such that the microparticles formed, modified, or coated in the first stage will be effectively transferred to the second stage without collection between the zones. In some embodiments, the flowing carrier gas and / or the applied electric field (e.g., using an external bias plate) facilitate the transfer of the microparticles from the first zone to the second zone. In some embodiments, one or more coupling zones are disposed between the first zone and the second zone to facilitate the transfer of the microparticles from the first zone to the second zone. In some embodiments, the first zone and the second zone together with any coupling zones therebetween are shielded (e.g., by a dielectric material, or a dielectric coating) to reduce the amount of charged species recombination. By preventing recombination, the shielding can increase the output ionization efficiency (i.e., increase the fraction of ionized microparticles or other species output from the first zone). In some embodiments, magnetic shielding will be used to prevent recombination and provide a higher output ionization efficiency. In some embodiments of the present plasma spraying system, the third zone includes an electric field, wherein a plurality of ionized particles are accelerated by the electric field to form a plasma spray including the ionized particles. In some embodiments, the accelerated particles are then deposited as a thin film on a substrate. For example, an electric field can be formed in the third zone by applying a potential between a first (e.g., annular or porous) electrode and a porous electrode (e.g., a screen) or the substrate, such that the ionized particles are accelerated through the porous electrode onto the substrate to form a high-quality (e.g., dense) thin film. In some embodiments, the pressures in all three zones of the plasma spraying system described herein are the same (or similar), while in other embodiments, the pressures in each zone can be different. In some embodiments, all zones are maintained at atmospheric pressure, near atmospheric pressure, or low pressure. For example, the pressure in one, two, three, or all of these zones can be from 0.1 atmospheres to 10 atmospheres, or from 0.5 atmospheres to 10 atmospheres, or from 0.9 atmospheres to 10 atmospheres, or greater than 0.1 atmospheres, or greater than 0.5 atmospheres, or greater than 0.9 atmospheres. Several non-limiting example embodiments of the plasma spraying system and method described above will now be described. FIG. 1A is a flowchart of a method 100 using the present plasma spraying system 102 according to some embodiments. In a first step 110 occurring in the first zone of the plasma spraying system (as described above), a material is formed and / or the input material is coated with another substance (such as particles sputtered from a target material). A second step 120 occurring in the second zone of the plasma spraying system involves gas and material ionization, and plasma jet generation. In a third step 130 occurring in the third zone of the plasma spraying system, the ionized material is accelerated, thereby imparting high energy to the ionized material for coating the substrate. Figure 1B is a simplified schematic example of the present plasma torch (i.e., plasma spraying system) 102 according to some embodiments. The plasma torch has a configuration of three zones 140, 150, and 160 that perform the processes described in the three steps shown in Figure 1A. The three zones shown in Figure 1B correspond to the three zones described above according to some embodiments. The first zone 140 is a coating and / or forming zone, the second zone 150 is an ionization zone, and the third zone 160 is an acceleration zone. Also shown in Figure 1B are two inlets 172 and 174 for the input materials - according to some embodiments, one inlet 172 is for inputting gas and one inlet 174 is for inputting particulates. The figure shows the input gas inlet 172 coupled to the first zone 140. In some embodiments, the input gas inlet is coupled to the first zone 140, or the second zone 150, or there may be more than one input gas inlet coupled to the first zone and / or the second zone. In some cases, the input particulates are input into the inlet 174 as a colloidal dispersion of particulates mixed with gas and / or liquid. In the example shown in Figure 1B, the first zone 140 includes a target (i.e., target material) 182, and ionic species (not shown) are formed from the target 182, and these ionic species form particulates (not shown), or coat the input particulates 104. The second zone 150 includes a microwave energy input 184, and in this zone, a microwave plasma is formed from the input gas provided to the second zone 150 (e.g., the gas that is freely coupled to the inlet 172 of the first zone, or the gas that is introduced into the system 102 through a direct-coupled inlet (not shown) in the second zone and flows through the first zone). The microwave plasma further ionizes the particulates or coated particulates 106 output from the first zone 140. In some cases, the microwave plasma ionizes some of the atoms in the particulates or coated particulates 106 output from the first zone 140 to form ionized particulates 108 (i.e., not all of the atoms constituting the particulates are necessarily ionized in the second zone). A plasma jet 190 (i.e., torch flame) is output from the second zone 150. The plasma jet 190 output from the second zone 150 can be generated, confined, and / or guided using only the microwave energy in the second zone 150 or by adding additional energy (e.g., using an additional electric or magnetic field from an electrode and / or a magnet). The third zone 160 in the figure includes a first porous electrode 192 (e.g., a screen that allows the ionized particulates 108 and 194 to pass through), and the first porous electrode 192 accelerates the ionized particulates 194 towards the substrate 165 via a potential gradient 196 (or a gradient of increasing energy), and a coating 175 (i.e., a thin film or layer) is deposited on the substrate 165. In some embodiments, microwave (MW) energy is directly input into a second zone (e.g., 150 in FIG. 1B) by bypassing a first zone (e.g., 140 in FIG. 1B). This can be achieved, for example, using a waveguide that couples a microwave energy source to the second zone. In other embodiments, MW energy is input into the second zone (e.g., 150 in FIG. 1B) via the first zone (e.g., 140 in FIG. 1B). For example, the MW can be input into the first zone and pass through the first zone (interacting or not interacting with the gas and / or particles in the first zone) and enter the second zone. This can be achieved, for example, using a waveguide that passes through the first zone (e.g., the chamber forming the first zone itself can form part of the waveguide) to couple the microwave energy source to the second zone. In some cases, the first zone can act as a chamber for material formation and act as a waveguide to transfer microwave energy from the microwave energy source to the second zone. In some embodiments, a plasma spray system 103 is shown in FIG. 1C and utilizes CVD techniques to generate ionic species from input materials (e.g., input gases) in a first zone. The plasma spray system 103 is similar to the system 102 shown in FIG. 1B and contains many of the same components, except that it does not have a target 182 in the first zone and instead has an energy input 186. Instead of using PVD techniques, the energy input 186 provides energy to the plasma spray system 103 to drive a CVD reaction to generate ionic species from input materials (e.g., input gases) in the first zone. The ionic species generated by CVD can condense to form particles, or can coat input particles that have been input into the first zone. The energy input 186 is used to provide energy to the first zone so that the CVD reaction can occur in the first zone. This energy input 186 can input any type of energy into the first zone that can drive the CVD reaction. For example, the energy input 186 can be a microwave energy input (similar to the microwave energy input 184 into the second zone), or it can be a thermal energy input (e.g., using a resistive heater). FIG. 2 is a flowchart of a method 200 of using the present plasma spraying system according to some embodiments, the method 200 having more details of the three steps 110, 120, and 130 in method 100 (e.g., occurring in regions 140, 150, and 160 of the plasma plume 102 in FIG. 1B). The first step 210 involves coating an input particulate material or forming a particulate from a material synthesis, and can occur in a first region of the plasma spraying system (e.g., 140 in FIG. 1B). In step 210, the material is deposited onto the particulates and / or gas-phase particulates are formed with or without the input of a nucleating material. In some embodiments, the first step 210 includes depositing the material onto the particulates in one or more sub-layers to form one or more coating layers. The first step 210 may also include forming particulates from the gas phase with or without the input of a nucleating material. In some embodiments, PVD (e.g., using a target material) or CVD (e.g., thermal or plasma-enhanced) methods are used to produce or coat the particulates in the first step 210. The second step 220 includes ionization fraction enhancement (e.g., using microwave energy, or high-frequency RF energy), and can occur in a second region of the plasma spraying system (e.g., 150 in FIG. 1B). In the second step 220, the material formed and / or coated in the first step 210 is further ionized, and a plasma gas torch (i.e., a plasma jet) is produced as an output. The third step 230 includes accelerating the ionized material produced in the second step 220, and can occur in a third region of the plasma spraying system (e.g., 160 in FIG. 1B). In the third step 220, an electric field (e.g., from a DC / AC, or high-frequency RF potential) is used to accelerate the charged ionized plasma-carried material species (i.e., the plasma jet) and the material species impinge on a biased or unbiased substrate to form a thin film on the substrate. The acceleration in the third step 230 has the benefit of improving the quality of the thin film growth and / or the fill density of the thin film on the substrate. In some embodiments, the acceleration in the third step 230 enables the ionized material to become embedded (i.e., implanted below) beneath the surface of the growing coating deposited on the substrate, which improves the fill density of the growing coating (e.g., reduces the amount of voids). In some embodiments, the acceleration in the third step 230 enables the ionized material to become embedded beneath the surface of the substrate, providing anchoring for subsequent material deposition and / or improving the adhesion of the coating to the substrate. Examples of coated microparticles that can be generated by the systems and methods described herein (e.g., in FIGS. 1A and 2, respectively) are carbon microparticles coated with a low melting point metal such as aluminum (e.g., less than or equal to 1000 °C, or less than or equal to 800 °C, or less than or equal to 600 °C). The carbon microparticles can be generated in zone 1 or input into zone 1 as input microparticles. Then in zone 2, a low melting point metal such as aluminum can be deposited onto the carbon microparticles using any one of the PVD or CVD techniques described herein (e.g., sputtering from a metal target). Since the metal has a low melting point and the carbon allotropes have a high melting point (e.g., about 1500 °C), the metal can be coated onto the carbon microparticles at a temperature that does not interfere with or damage the morphology of the carbon microparticles (e.g., substantially at, or slightly above, the melting point of the metal). For example, the carbon microparticles can have a 3D mesoporous morphology beneficial for end-use applications (e.g., battery electrodes), and the low melting point metal can be deposited on the carbon microparticles without changing the morphology of the carbon microparticles underlying the metal coating. In some embodiments, the coated metal microparticles can then be accelerated in a third zone and deposited as a dense film on a substrate, where the film contains carbon microparticles having a beneficial morphology intact within the low melting point metal matrix. FIG. 3 shows a simplified schematic section 300 of an embodiment in which the plasma-based coating technique for the first stage (e.g., zone 140 of FIG. 1B, and / or in a system capable of performing step 210 of method 200) is sputtering, according to some embodiments. In this embodiment, a particulate input material 104 (e.g., a colloidal dispersion) is inserted into the system (e.g., system 102 of FIG. 1B) and the particulate input material 104 is coated with a coating material by sputtering to produce a coated microparticle 106 output from a first zone (e.g., 140 of FIG. 1B). In such systems, an input gas shown as "Ar" in the figure generates an ionic species shown as "M" in the figure from a target 182. The ionic species is deposited on the surface of the input particulate material 104 to form the coated particulate material 106. In other embodiments (not shown in the figure), there is no input particulate material and the ionic species "M" generated from the target 182 combines to form microparticles from the gas phase. In some cases, reactive sputtering is used in the first step and / or zone shown in FIG. 3, and the coating and / or microparticles formed can be a compound including the target material and another input gas (shown as "O" in the figure) 2compounds of ")". The use of "Ar" and "M" in the figure is only a non-limiting example, and other input gases (e.g., argon, nitrogen, and oxygen) and ionized substances (e.g., metals, semiconductors, or insulators) can also be utilized in the present system and method. For example, sputtering is a general technique capable of producing many different elemental and compound materials, and many of these materials in different embodiments are compatible with the present system and method. Some non-limiting examples of sputtered coatings and / or particles that can be formed in the first step and / or zone of the plasma spraying methods and systems described herein are carbon allotropes, sulfur, silicon, iron, nickel, and manganese, as well as elemental metals, metal alloys, metal oxides, and metal nitrides. In the first zone of the example shown in FIG. 3, the target 182 can be in any form factor, such as a disk, tube, wire, powder, or a coating on a surface. For example, the target 182 can be a tube that forms the wall of the chamber containing the first zone 140. In some embodiments, the target 182 can be continuously or intermittently replenished while the system is in operation. For example, the target 182 can be a powder replenished using a particle delivery system that feeds the particles into the first zone, where the particles are fully or partially converted into ionized substances. In another example, the target 182 can be a wire, or a plurality of wires, replenished using a wire feedthrough device. In some embodiments, high power impulse magnetron sputtering (HIPIMS) can be used to generate ionized substances from the target 182 and form or coat particles 104 in the first stage (e.g., zone 140 in FIG. 1B). For example, the power supply in the first stage can be configured for HIPIMS and supply 1 to 100 kW-cm of power density in pulses that are 1 to 100 microseconds long at a duty cycle of 1 to 25%. -2 The advantage of using HIPIMS in the first stage is that the generated ionized substances have a high degree of ionization of the input gas (e.g., Ar) and / or a high molecular gas dissociation rate, both of which result in high-quality density (e.g., low porosity) of the generated particles or deposited coatings. In some embodiments, the average cathode power in the HIPIMS system is 0.1 to 1000 W-cm -2 . In some embodiments, a power supply with a high voltage (e.g., about 3 kV or 1 to 10 kV) and a pulsed output (e.g., 1 to 100 microseconds long at a duty cycle of 1 to 25%) can be used in the first zone to form or coat particles. This power supply can be coupled to the target 182 and generate ionized substances from the target 182 in the first zone. In other cases, this power supply can be used in a CVD or PECVD system in the first zone. FIG. 4 shows a simplified schematic section 400 of an exemplary plasma spray system having an enhanced ionization fraction in a second stage 450 (e.g., region 150 in FIG. 1B and / or in a system capable of performing step 220 of method 200), the enhanced ionization fraction being for further ionization of coated or generated particulates from a first stage. The figure shows microwave energy 410 within a chamber 402 in a second zone. Particulates or coated particulates 404a flow through the chamber and are modified by a microwave plasma such that the ionization density ρ of the particulates e is enhanced or increased as it flows through the chamber. This is shown in the figure as elements 420a-d, whose density increases from left to right in the figure. Similarly, the particulates 404a have a low ionization density ρ e upon entering this second stage and the particulates 404b and 404c have an increasingly higher ionization density ρ e as the particulates move further through the second stage. The particulates 404d have a high ionization density and are output from the second stage (e.g., for deposition on a substrate 165). Also shown is a surface wave plasma 430 with microwave energy propagation in a transverse electromagnetic mode (TEM). In this form of wave propagation, the current flows towards and is adsorbed to points where it forms a conductor that can reach a critical number density. This critical number density can then stop adsorbing microwave energy and can deliver the energy to other regions, thereby propagating the energy within the chamber. As previously described, there are several different ways to couple microwave energy into the chamber (e.g., coaxial feed, or energy propagation using TE, TM, or TEM modes), and different coupling methods can be employed in different embodiments of the present system and method. Depending on the coupling method, the geometry of the chamber can be important. For example, the chamber itself can act as a waveguide for the microwave energy and the propagation direction can be parallel or perpendicular to the particulate flow through the second zone. In some embodiments, other features not shown in the example of FIG. 4 may include filaments, point sources, electrodes, and / or magnets in the microwave plasma zone of the second zone to improve plasma density and / or assist in plasma ignition. FIG. 5 shows an example of a plasma moment 500 having a first stage 540, the first stage 540 having a plurality of material sputtering sub-regions 540a and 540b. The plurality of sub-regions 540a and 540b within the first region 540 enable a plurality of coatings to be deposited on the input particles such that the particles are formed in the first sub-region and then coated in the second sub-region, and / or different types of particles are formed in the first sub-region and the second sub-region. Non-limiting examples shown in FIG. 5 include particles 104 input to the first stage, the particles 104 being coated in the first sub-region 540a of the first stage 540 using target 182a to form coated particles 106a, and then the coated particles 106a being coated with a second coating layer using target 182b in the second sub-region 540b of the first stage 540 to form second coated particles 106b. For example, materials for Li-ion battery electrodes having multiple coating layers can be formed in a system having multiple sub-regions within the first region. In this example, porous carbon particles 104 (e.g., containing an ordered graphene phase) can be input into the first region, and the surface area can be increased by depositing a coating of orthogonally grown carbon onto the input particles in the first sub-region 540a. In the second sub-region 540b, the coated particles 106a can be further coated with a solid electrolyte interface (SEI) layer (e.g., silicon and / or sulfur) to form particles 106b. These multi-layer coated particles can be used in a battery to enhance battery performance. Compared to methods that rely on sequential coating steps, using this multi-stage plasma moment to form multi-layer battery materials is advantageous for improving battery performance and reducing manufacturing costs. FIG. 5 also shows a magnetically enhanced plasma region for improving plasma efficiency according to some embodiments. In some embodiments, the deposition rate of the material in the first region (or sub-regions of the first region) is improved using magnets 550a-d coupled to the first region, the second region, and / or the third region. In some cases, certain target materials require a high surface ion density to achieve an appreciable deposition rate, and adding magnets 550a-b in the region having the target can increase the density of surface ions by confining electrons (i.e., a "magnetic bottle" can be formed using a magnetic field). In different embodiments, the magnets can be permanent magnets or electromagnets. FIG. 5 also shows that permanent magnets or electromagnets 550c-d can be used to confine or guide the microwave plasma in the second region to increase the plasma density and / or form or guide the particles in the plasma jet 190. In some cases, an external magnet (permanent magnet or electromagnet) is used to increase the ionization efficiency in the first region and / or the second region. Figures 6 and 7 illustrate plasma torches 600 and 700 that are examples of different configurations of a system for accelerating ionized materials according to some embodiments. These plasma torches are similar to plasma torches 102, 400, and 500 and contain similar components; however, not all components are labeled in Figures 6 and 7. To form high-quality thin films on biased or unbiased substrates, the acceleration of charged, ionized material species (i.e., the plasma jet output from the second stage) is advantageous. Figure 6 illustrates plasma torch 600, which has a configuration similar to that shown for plasma torch 102 in Figure 1B and includes a porous electrode 192 (e.g., a screen that allows ionized particles to pass through), which accelerates ionized particles toward substrate 165 via a potential gradient 196 (or an increasing energy gradient) to form a coating (i.e., a thin film or layer) on substrate 165. In this configuration, a potential is applied between a first electrode 610 at or near the exit of the second zone of plasma torch 600 and the porous electrode 192 using a power source 620. The power source 620 can be a high-voltage power source that applies a large potential between the electrode 610 and the porous electrode 192. The first electrode 610 can be a solid electrode (e.g., a porous or annular electrode that allows ionized particles to pass through), or the plasma in the second zone can act as the first electrode 610. The potential applied in this example can be a DC, pulsed DC, or AC voltage. The applied voltage can be any voltage (e.g., 25 V to 10 kV) and typically depends on the application. Figure 7 illustrates plasma torch 700 that is an example of two different configurations of a system for accelerating ionized materials according to some embodiments. In a first example, a high-voltage power source 720 applies a potential between an electrode 710 (e.g., a porous or annular electrode that allows ionized particles to pass through) and substrate 165. In a second example, the electrode 710 is grounded and an RF power source 730 is used to bias the substrate 165 to generate an electric field that accelerates the plasma jet onto the substrate. The high voltage applied in either of these examples can be a DC, pulsed DC, or AC voltage. In some embodiments, the output of the plasma spraying system described herein is directed to a substrate to form a coating on the substrate. In some embodiments, a single head outputs a stream of ionized particles onto the substrate. In other embodiments, multiple heads are configured in parallel to output multiple streams of ionized particles onto the substrate. In other embodiments, a single head or multiple heads output one or more streams of ionized particles onto the substrate, and scan one or more heads across the substrate to increase coverage across the substrate. FIG. 8 shows a simplified schematic illustration of an example of a plasma spraying system 800 having multiple heads 810a-e that deposit streams of ionized particles 820a-e onto a substrate 165. In some embodiments, each head 810a-e is similar to the system shown in FIG. 1B and / or any of FIGS. 3-7. FIG. 8 also shows that optionally, the plasma spraying system 800 having multiple heads 810a-e can be scanned across the substrate 165 in direction 830 to increase coverage. In some plasma spraying embodiments, the third stage may be omitted. In such cases, the plasma jet output from the second stage can be directed to the substrate to form a coating without the high acceleration provided by the third stage. In some plasma spraying embodiments, the second stage may be omitted. In such cases, the particles formed, modified, or having a coating output from the first stage can be directly fed to the third stage for acceleration and, in some cases, directed to the substrate to form a coating. In some embodiments, the output of a reactor for generating particulate material can be connected to the input of the first stage of the present plasma spraying system. For example, a microwave plasma reactor can be used to generate particulate material, and the particles output from the reactor are input into the first stage (i.e., the particles are not collected between the reactor and the plasma spraying system). In some embodiments, the hot flue gas stream and / or afterglow output from the reactor can also be input into the first stage of the present plasma spraying system together with the generated particulate material. Some examples of microwave plasma reactors that can be coupled to the input of the present plasma spraying system are described in U.S. Patent No. 9,812,295 or U.S. Patent No. 9,767,992, which are incorporated herein by reference for all purposes as if fully set forth herein. In another example, a pyrolysis reactor can be used to generate particulate material, and the particles output from the reactor are input into the first stage of the present plasma spraying system. Some examples of thermal reactors that can be coupled to the input of the present plasma spraying system are described in U.S. Patent No. 9,862,602 titled "Cracking of a Process Gas", which is assigned to the same assignee as the present application and is incorporated herein by reference for all purposes as if fully set forth herein. The particles and coatings produced using the plasma spraying systems and methods described herein have many applications, including different types of mechanical, electrical, and optical applications. For example, the plasma-sprayed coatings can be applied to improve the mechanical properties of structural materials, form thermal barrier coatings, or prevent corrosion, erosion, or wear of a surface or object. The plasma-sprayed coatings can also be used to alter the optical, electrical, magnetic, or frictional properties of a surface or object. One example application of the plasma-sprayed coatings is electrodes in high-capacity lithium-ion batteries. For example, carbon-based particulate particles having a high surface area to volume ratio and / or having a beneficial morphology for charge extraction during battery operation can be introduced into the system. The input particles can then be coated in a first stage (e.g., using sputtering) with one or more active battery electrode materials (e.g., sulfur or silicon). The coated particles can then be further ionized in a second stage and accelerated in a third stage and deposited onto a conductive substrate to form a dense, high-quality thin film for a battery electrode. In some embodiments, a plasma spraying method (e.g., in some embodiments, similar to method 100 in FIG. 1A) includes: generating a plurality of ionic species from a target material to form a plurality of particles; ionizing the plurality of particles to form a plurality of ionized particles and generating a plasma jet including the plurality of ionized particles; and accelerating the plurality of ionized particles to form a plasma spray including the ionized particles. In some embodiments, the plurality of accelerated ionized particles are then directed to a substrate and the ionized particles form a coating on the substrate. In some embodiments, a plasma spraying method (e.g., in some embodiments, similar to method 100 in FIG. 1A) includes supplying a plurality of input particles and generating a plurality of ionic species from a target material, wherein the ionic species form a coating on the input particles to form a plurality of coated particles. The plurality of coated particles are then ionized to form a plurality of ionized particles and a plasma jet including the plurality of ionized particles is generated. The plurality of ionized particles are then accelerated in a third stage to form a plasma spray including the ionized particles. In some embodiments, the plurality of accelerated ionized particles are then directed to a substrate and the ionized particles form a coating on the substrate. Depending on the conditions in the plasma plume, the plasma (e.g., in the second zone) can be a thermal plasma where various degrees of freedom are close to thermal equilibrium, or a cold plasma where, for example, the translational degrees of freedom of molecules, atoms, and ions are only excited to an equivalent temperature that is much colder than the higher temperature corresponding to the energy in the degrees of freedom associated with ionization and / or excitation of atomic and molecular species. Parameters for forming thermal and cold plasmas that can be used to modify the formation of materials described herein include controlling plasma pressure, current duration and duty cycle, pulsation of the power supply, and the presence or absence of a material having, for example, a high or low electron capture cross section. These plasma formation parameters can be tuned based on, for example, the type of input material and the particle size being processed. Depending on the conditions in the plasma plume, the plasma (e.g., in the second zone) can be a thermal plasma where various degrees of freedom are close to thermal equilibrium, or a cold plasma where, for example, the translational degrees of freedom of molecules, atoms, and ions are only excited to an equivalent temperature that is much colder than the higher temperature corresponding to the energy in the degrees of freedom associated with ionization and / or excitation of atomic and molecular species. Parameters for forming thermal and cold plasmas that can be used to modify the formation of materials described herein include controlling plasma pressure, current duration and duty cycle, pulsation of the power supply, and the presence or absence of a material having, for example, a high or low electron capture cross section. These plasma formation parameters can be tuned based on, for example, the type of input material and the particle size being processed. Thermal plasma can be particularly effective in promoting melting of the particles (e.g., in the second zone), while cold plasma can be more effective in modifying surface physics and chemistry without completely melting the particles. In addition to the plasma generated, the plasma plume can also include a high voltage DC or high voltage low frequency AC bias between the torch and the substrate on which the material is deposited, such that a substantial potential exists between the torch body and the substrate, and / or a substantial current flows between the torch and the substrate. The voltage difference between the torch and the substrate can be greater than 100 kV, or greater than 30 kV, or greater than 10 kV, or greater than 3 kV. The current between the torch and the substrate can be greater than 100 amperes, or greater than 10 amperes, or greater than 1 ampere. The above voltage between the torch and the substrate and / or the coating of the formed material will help accelerate the particles towards the substrate to modify the degree to which the particles are embedded in the matrix of the substrate. In some embodiments, for example, given a yield strength of approximately 100 MPa for a substrate, and a charge of approximately 10,000 e (where e is the elementary charge) on the particles, and a particle size of approximately 1 micron, a voltage gain of approximately 30 kV will help embed the particles in the matrix of the substrate. Equivalent energy can be obtained by the gas dynamic co-flow in the plasma that accelerates the particles to a speed of 100 m / s or several times greater than 100 m / s (e.g., 100 m / s to 1000 m / s). In some embodiments, the high current between the torch and the substrate and / or coating will enhance the formation of hybrid covalent - metallic signature bonds between carbon and metal. For example, carbon particles can be introduced into the first zone and the carbon particles can be coated with metal from the target material in the first zone, and the resulting composite particles can be accelerated onto the substrate to form a dense film containing hybrid covalent - metallic signature bonds between carbon and metal. In some embodiments, the thin - film or coating deposition conditions can be tuned to customize the density of the resulting bulk or thin - film material. For example, the particles synthesized via the torch can be ionized by tuning the plasma - power supply power to current and heated via ion bombardment within the second zone of the torch. This tuning of the conditions within the torch can trim the compositionally combined materials within a range of states - such as from liquid to semi - solid states - such that the density of the material to be deposited can be controlled from fully densified to a more porous nature. Additionally, the output accelerator field within the third zone can be set to various voltages to implant the material, such as using a low voltage level to gently bond the formed material to the substrate surface. FIG. 9 is a flowchart of a method 900 of using a plasma - spraying system according to some embodiments. In step 910, a plasma - spraying system including three zones is provided. The first zone includes a target material and a device having a power source, the second zone is connected to the output of the first zone and includes a chamber coupled to a microwave - energy source, and the third zone is connected to the output of the second zone and includes an electric field. In step 920, a plurality of ionic species are generated from the target material using energy from the power source in the first zone. In step 930, the ionic species are combined in the first zone to form a plurality of particles. In step 940, microwave energy is supplied to the chamber using the microwave - energy source in the second zone to ionize the plurality of particles and form a plurality of ionized particles. In step 950, a plasma jet including the plurality of ionized particles is generated in the second zone. In step 960, the plurality of ionized particles are accelerated using the electric field in the third zone to form a plasma spray including the ionized particles. FIG. 10 is a flowchart of a method 1000 using a plasma spraying system according to some embodiments. In step 1010, a plasma spraying system including three zones is provided. The first zone includes a target material and a device having a power source, the second zone is connected to the output of the first zone and includes a chamber coupled to a microwave energy source, and the third zone is connected to the output of the second zone and includes an electric field. In step 1015, a plurality of input particles are input into the first zone. In step 1020, a plurality of ionic substances are generated from the target material using energy from the power source in the first zone. In step 1030, the ionic substances are combined in the first zone to form a coating on the plurality of input particles. In step 1040, microwave energy is supplied to the chamber using the microwave energy source in the second zone to ionize the plurality of coated particles and form a plurality of ionized particles. In step 1050, a plasma jet including the plurality of ionized particles is generated in the second zone. In step 1060, the plurality of ionized particles are accelerated using the electric field in the third zone to form a plasma spray including the ionized particles. In method 900 or 1000, the ionic substances can be generated from the target material using energy from the power source by one or more processes among physical vapor deposition, thermal evaporation, sputtering, and pulsed laser deposition. Method 900 or 1000 may further include a step in which a plurality of ionized particles are accelerated by an electric field to form a coating on a substrate. In some embodiments, a plasma spraying system includes: an inlet where one or more input gases are input into the system; a first zone that includes a reaction zone where: one or more input gases are input into the first zone via the inlet; the reaction zone is configured to generate a plurality of ionic substances from the input gases; and the ionic substances are combined to form a plurality of particles; a second zone connected to the outlet of the first zone, the second zone including a chamber coupled to a microwave energy source where: the microwave energy source supplies microwave energy to the chamber to ionize the plurality of particles to form a plurality of ionized particles; and a plasma jet including the plurality of ionized particles is generated; and a third zone connected to the outlet of the second zone, the third zone including an electric field where the plurality of ionized particles are accelerated by the electric field to form a plasma spray including the ionized particles. In some embodiments of the plasma spraying system above, the plurality of particles are generated from the input gases by one or more processes among chemical vapor deposition and plasma-enhanced chemical vapor deposition. In some embodiments of the plasma spraying system above, the plurality of particles include materials selected from the group consisting of carbon allotropes, ZnO, SiO, SiC, AlC, FeSi, and NiO. In some embodiments of the plasma spraying system above, the plurality of ionized particles are accelerated by an electric field to form a coating on a substrate. In some embodiments, a plasma spraying system includes: a first inlet through which a plurality of input particles are input into the system; a second inlet through which one or more input gases are input into the system; a first zone that includes a reaction zone, wherein: the plurality of input particles are input into the first zone through the first inlet; the one or more input gases are input into the first zone through the second inlet; the reaction zone is configured to generate a plurality of ionic species from the input gases; and the ionic species combine to form a coating on the plurality of input particles to form a plurality of coated particles; a second zone connected to the outlet of the first zone, the second zone including a chamber coupled to a microwave energy source, wherein: the microwave energy source supplies microwave energy to the chamber to ionize the plurality of coated particles to form a plurality of ionized particles; and a plasma jet including the plurality of ionized particles is generated; and a third zone connected to the outlet of the second zone, the third zone including an electric field, wherein the plurality of ionized particles are accelerated by the electric field to form a plasma spray including the ionized particles. In some embodiments of the plasma spraying system above, the plurality of input particles include: carbon allotropes, silicon, carbon, aluminum, ceramics, FeSi, SiOx, materials with high permeability, nickel-iron soft ferromagnetic alloys, materials with high relative permittivity, high-k dielectric materials, perovskites, high conductivity materials, or metals. In some embodiments of the plasma spraying system above, the plurality of particles are generated from the input gases by one or more processes of chemical vapor deposition and plasma-enhanced chemical vapor deposition. In some embodiments of the plasma spraying system above, the coating on the plurality of input particles includes materials selected from the group consisting of: carbon, sulfur, silicon, iron, nickel, manganese, metal oxides, ZnO, SiO, NiO, metal carbides, SiC, AlC), metal silicides, FeSi, metal borides, metal nitrides, SiN, and ceramic materials. In some embodiments of the plasma spraying system above, the plurality of ionized particles are accelerated by the electric field to form a coating on a substrate. In some embodiments, a method includes: generating a plurality of ionic species from a target material to form a plurality of particles; ionizing the plurality of particles to form a plurality of ionized particles and generating a plasma jet including the plurality of ionized particles; and accelerating the plurality of ionized particles to form a plasma spray including the ionized particles. In some embodiments of the method above, the plurality of ionic species are generated from the target material by one or more processes of physical vapor deposition, thermal evaporation, sputtering, and pulsed laser deposition. In some embodiments of the above method, the plurality of microparticles comprise materials selected from the group consisting of: carbon allotropes, ZnO, SiO, SiC, AlC, FeSi, and NiO. In some embodiments of the above method, a microwave plasma is used to ionize the plurality of microparticles. In some embodiments, the above method further comprises directing the plurality of ionized microparticles towards a substrate and forming a coating on the substrate. In some embodiments, a method comprises: supplying a plurality of input microparticles; generating a plurality of ionic species from a target material, wherein the ionic species form a coating on the input microparticles to form a plurality of coated microparticles; ionizing the plurality of coated microparticles to form a plurality of ionized microparticles and generating a plasma jet comprising the plurality of ionized microparticles; and accelerating the plurality of ionized microparticles to form a plasma spray comprising the ionized microparticles. In some embodiments of the above method, the plurality of input microparticles comprise: carbon allotropes, silicon, carbon, aluminum, ceramics, FeSi, SiOx, materials with high permeability, nickel-iron soft ferromagnetic alloys, materials with high relative permittivity, high-k dielectric materials, perovskites, high conductivity materials, or metals. In some embodiments of the above method, the ionic species are generated from the target material by one or more processes of physical vapor deposition, thermal evaporation, sputtering, and pulsed laser deposition. In some embodiments of the above method, the coating on the plurality of input microparticles comprises materials selected from the group consisting of: carbon, sulfur, silicon, iron, nickel, manganese, metal oxides, ZnO, SiO, NiO, metal carbides, SiC, AlC), metal silicides, FeSi, metal borides, metal nitrides, SiN, and ceramic materials. In some embodiments of the above method, a microwave plasma is used to ionize the plurality of coated microparticles. In some embodiments, the above method further comprises directing the plurality of ionized microparticles towards a substrate and forming a coating on the substrate. From the above discussion, it will be appreciated that the present invention can be embodied in a variety of specific forms, including but not limited to the following: Specific Example 1. A plasma spraying system, the plasma spraying system comprising: A first region, the first region comprising a target material and a device having a power source, wherein: The power source is configured to generate a plurality of ionic substances from the target material using the energy from the power source; and The ionic substances combine to form a plurality of microparticles; A second region, the second region connected to an output end of the first region, the second region comprising a chamber coupled to a microwave energy source, wherein: The microwave energy source supplies microwave energy to the chamber to ionize the plurality of microparticles to form a plurality of ionized microparticles; and A plasma jet comprising the plurality of ionized microparticles is generated; and A third region, the third region connected to an output end of the second region, the third region comprising an electric field, wherein the plurality of ionized microparticles are accelerated by the electric field to form a plasma spray comprising the ionized microparticles. Specific Example 2. The plasma spraying system according to Specific Example 1, wherein the ionic substances are generated from the target material by one or more processes of physical vapor deposition, thermal evaporation, sputtering, and pulsed laser deposition using the energy from the power source. Specific Example 3. The plasma spraying system according to Specific Example 1, wherein the plurality of microparticles comprise materials selected from the group consisting of carbon allotropes, ZnO, SiO, SiC, AlC, FeSi, and NiO. Specific Example 4. The plasma spraying system according to Specific Example 1, wherein the plurality of ionized microparticles are accelerated by the electric field to form a coating on a substrate. Specific Example 5. The plasma spraying system according to Specific Example 4, the plasma spraying system further comprising a high voltage power source, the high voltage power source connected to a first electrode in the third region and a porous electrode located between the third region and the substrate to generate the electric field in the third region and accelerate the ionized microparticles. Specific Example 6. The plasma spraying system according to Specific Example 4, the plasma spraying system further comprising a high voltage power source, the high voltage power source connected to a first electrode in the third region and the substrate to generate the electric field in the third region and accelerate the ionized microparticles. Specific Example 7. The plasma spraying system according to Specific Example 4, the plasma spraying system further comprising a high voltage power source, the high voltage power source connected to the substrate to generate the electric field in the third region and accelerate the ionized microparticles. Specific Example 8. The plasma spraying system according to Specific Example 1, the plasma spraying system further comprising external magnets coupled to the first region, the second region, or the third region, wherein the magnets are permanent magnets or electromagnets. Specific Example 9. A plasma spraying system, the plasma spraying system comprising: a first zone, the first zone comprising: an inlet, wherein a plurality of input particles are input into the first zone; a target material; and a device having a power source, wherein: the power source is configured to generate a plurality of ionic substances from the target material using energy from the power source; and the ionic substances combine to form a coating on the plurality of input particles to form a plurality of coated particles; a second zone, the second zone connected to an output end of the first zone, the second zone comprising a chamber coupled to a microwave energy source, wherein: the microwave energy source supplies microwave energy to the chamber to ionize the plurality of coated particles to form a plurality of ionized particles; and a plasma jet comprising the plurality of ionized particles is generated; and a third zone, the third zone connected to an output end of the second zone, the third zone comprising an electric field, wherein the plurality of ionized particles are accelerated by the electric field to form a plasma spray comprising the ionized particles. Specific Example 10. The plasma spraying system according to Specific Example 9, wherein the plurality of input particles comprise materials selected from the group consisting of: carbon allotropes, silicon, carbon, aluminum, ceramics, FeSi, SiO x , materials with high permeability, nickel-iron soft ferromagnetic alloys, materials with high relative permittivity, high-k dielectric materials, perovskites, and high-conductivity materials, metals. Specific Example 11. The plasma spraying system according to Specific Example 9, wherein the plurality of ionic substances are generated from the target material using the energy from the power source by one or more processes of physical vapor deposition, thermal evaporation, sputtering, and pulsed laser deposition. Specific Example 12. The plasma spraying system according to Specific Example 9, wherein the coatings on the plurality of input particles comprise materials selected from the group consisting of: carbon, sulfur, silicon, iron, nickel, manganese, metal oxides, ZnO, SiO, and NiO, metal carbides, SiC, and AlC, metal silicides, FeSi, metal borides, metal nitrides, SiN, and ceramics. Specific Example 13. The plasma spraying system according to Specific Example 9, wherein the plurality of ionized particles are accelerated by the electric field to form a coating on a substrate. Specific Example 14. The plasma spraying system according to Specific Example 13, the plasma spraying system further comprising a high-voltage power source connected to a first electrode in the third zone and a porous electrode located between the third zone and the substrate to generate the electric field in the third zone and accelerate the ionized particles. Specific Example 15. The plasma spraying system as in Specific Example 13, the plasma spraying system further includes a high-voltage power supply, the high-voltage power supply is connected to a first electrode and the substrate in the third region to generate the electric field in the third region and accelerate the ionized particles. Specific Example 16. The plasma spraying system as in Specific Example 13, the plasma spraying system further includes a high-voltage power supply, the high-voltage power supply is connected to the substrate to generate the electric field in the third region and accelerate the ionized particles. Specific Example 17. The plasma spraying system as in Specific Example 9, the plasma spraying system further includes external magnets coupled to outside of the first region, the second region or the third region, wherein the magnets are permanent magnets or electromagnets. Specific Example 18. A method, the method includes: providing a plasma spraying system, the plasma spraying system includes: a first region, the first region includes a target material and a device having a power supply; a second region, the second region is connected to an output end of the first region, the second region includes a chamber coupled to a microwave energy source; and a third region, the third region is connected to an output end of the second region, the third region includes an electric field; using the energy from the power supply in the first region to generate a plurality of ionic substances from the target material; combining the ionic substances in the first region to form a plurality of particles; using the microwave energy source in the second region to supply microwave energy to the chamber to ionize the plurality of particles and form a plurality of ionized particles; generating a plasma jet including the plurality of ionized particles in the second region; and using the electric field in the third region to accelerate the plurality of ionized particles to form a plasma spray including the plurality of ionized particles. Specific Example 19. The method as in Specific Example 18, wherein the ionic substances are generated from the target material by one or more processes of physical vapor deposition, thermal evaporation, sputtering and pulsed laser deposition using the energy from the power supply. Specific Example 20. The method as in Specific Example 18, wherein the plurality of particles include materials selected from the group consisting of: carbon allotropes, ZnO, SiO, SiC, AlC, FeSi and NiO. Specific Example 21. The method as in Specific Example 18, wherein the plurality of ionized particles are accelerated by the electric field to form a coating on a substrate. Specific Example 22. A method, the method comprising: providing a plasma spraying system, the plasma spraying system comprising: a first zone, the first zone comprising: an inlet, wherein a plurality of input particles are input into the first zone, a target material, and a device having a power source; a second zone, the second zone connected to an output end of the first zone, the second zone comprising a chamber coupled to a microwave energy source; and a third zone, the third zone connected to an output end of the second zone, the third zone comprising an electric field; using energy from the power source in the first zone to generate a plurality of ionic substances from the target material; combining the ionic substances in the first zone to form a coating on the plurality of input particles to form a plurality of coated particles; using the microwave energy source in the second zone to supply microwave energy to the chamber to ionize the plurality of coated particles and form a plurality of ionized particles; generating a plasma jet comprising the plurality of ionized particles in the second zone; and using the electric field in the third zone to accelerate the plurality of ionized particles to form a plasma spray comprising the plurality of ionized particles. Specific Example 23. The method of Specific Example 22, wherein the ionic substances are generated from the target material using energy from the power source by one or more processes of physical vapor deposition, thermal evaporation, sputtering, and pulsed laser deposition. Specific Example 24. The method of Specific Example 22, wherein the coatings on the plurality of input particles comprise materials selected from the group consisting of carbon allotropes, ZnO, SiO, SiC, AlC, FeSi, and NiO. Specific Example 25. The method of Specific Example 22, wherein the plurality of input particles comprise materials selected from the group consisting of carbon allotropes, silicon, carbon, aluminum, ceramics, FeSi, SiO x , materials with high permeability, nickel-iron soft ferromagnetic alloys, materials with high relative permittivity, high-k dielectric materials, perovskites, and high-conductivity materials, metals. Specific Example 26. The method of Specific Example 22, wherein the plurality of ionized particles are accelerated by the electric field to form a coating on a substrate. Reference has been made to embodiments of the disclosed invention. Each example has been provided as an illustration of the technology, and not as a limitation of the technology. In fact, although the specification has been described in detail with respect to specific embodiments of the invention, it should be understood that those skilled in the art may readily conceive of alterations, variations, and equivalents of such embodiments upon obtaining an understanding of the foregoing. For example, features shown or described as part of one embodiment may be used with another embodiment to yield yet another embodiment. Accordingly, the subject matter is intended to embrace all such modifications and variations within the scope of the appended claims and their equivalents. Such and other modifications and variations of the invention may be practiced by those of ordinary skill in the art without departing from the scope of the invention, which is more particularly set forth in the appended claims. In addition, those of ordinary skill in the art will understand that the foregoing description is by way of example only and is not intended to limit the invention. 100: Method 102: Plasma Moment / Plasma Spraying System 103: Plasma Spraying System 104: Input Particles 106: Coated Particles 106a: Particle 106b: Particle 108: Ionized Particles 110: First Step 120: Second Step 130: Third Step 140: First Region 150: Second Region 160: Third Region 165: Substrate 172: Inlet 174: Inlet 175: Coating 182: Target Material 182a: Target 182b: Target 184: Microwave Energy Input 186: Energy Input 190: Plasma Jet 192: First Porous Electrode 194: Ionized Particles 196: Potential Gradient 200: Method 210: First Step 220: Second Step 230: Third Step 300: Section 400: Plasma Moment 402: Chamber 404a: Particle 404b: Particle 404c: Particle 404d: Particle 410: Microwave Energy 420a: Element 420b: Element 420c: Element 420d: Element 430: Surface Wave Plasma 450: Second Stage 500: Plasma Moment 540: First Stage 540a: Material Sputtering Sub-region 540b: Material Sputtering Sub-region 550a: Magnet 550b: Magnet 550c: Magnet 550d: Magnet 600: Plasma Moment 610: First Electrode 620: Power Supply 710: Electrode 720: High Voltage Power Supply 730: RF Power Supply 800: Plasma Spraying System 810a: Head 810b: Head 810c: Head 810d: Head 810e: Head 820a: Ionized Particle Stream 820b: Ionized Particle Stream 820c: Ionized Particle Stream 820d: Ionized Particle Stream 820e: Ionized Particle Stream 830: Direction 900: Method 910: Step 920: Step 930: Step 940: Step 950: Step 960: Step 1000: Method 1010: Step 1015: Step 1020: Step 1030: Step 1040: Step 1050: Step 1060: Step FIG. 1A is a schematic diagram of several stages in the present plasma spray deposition technique according to some embodiments. FIG. 1B is an example of a plasma moment according to some embodiments, the plasma moment having an example simplified configuration with three regions. FIG. 1C is an example of a plasma moment according to some embodiments, the plasma moment having an example simplified configuration with three regions. FIG. 2 summarizes the general high-level method of the plasma moment of the present embodiment, which involves material synthesis. FIG. 3 shows an example of one type of plasma-based coating technique - sputtering - according to some embodiments, which is used to coat microparticles of an input material with a coating material by sputtering or to form gas-phase microparticles. FIG. 4 shows an example of a plasma plume with enhanced ionization fraction according to some embodiments, which is used for further ionization of coated microparticles or substances. FIG. 5 shows an example of a plasma plume with multiple material sputtering regions and a magnetically enhanced plasma region for improving plasma efficiency according to some embodiments. FIG. 6 shows an example of a plasma plume with acceleration of ionized material according to some embodiments, which is used to accelerate the charged ionized material carried by the plasma onto a biased or unbiased substrate. FIG. 7 shows an example of a plasma plume with acceleration of material according to some embodiments. FIG. 8 shows a simplified schematic diagram of an example of a plasma spraying system with multiple heads according to some embodiments, which deposit a stream of ionized microparticles onto a substrate. FIGS. 9 and 10 are flowcharts of methods using a plasma spraying system according to some embodiments. 102: Plasma plume / plasma spraying system 104: Input microparticles 106: Coated microparticles 108: Ionized microparticles 140: First region 150: Second region 160: Third region 165: Substrate 172: Inlet 174: Inlet 175: Coating 182: Target material 184: Microwave energy input 190: Plasma jet 192: First porous electrode 194: Ionized microparticles 196: Potential gradient

Claims

1. A coating for spraying, comprising: a deposited layer of material on or within a substrate or forming a surface of a substrate; and a carbon-metal composite material at least partially within the deposited layer, the carbon-metal composite material comprising a plurality of particles, at least a portion of the plurality of particles having metallic bonds and at least a portion of the plurality of particles having covalent bonds.

2. The coating for spraying as claimed in claim 1, wherein the plurality of particles comprises a material selected from the group consisting of: carbon allotropes, ZnO, SiO, SiC, AlC, FeSi and NiO.

3. The coating for spraying as claimed in claim 1, wherein the plurality of particles comprises materials selected from the group consisting of: carbon, sulfur, silicon, iron, nickel, manganese, metal oxides, metal carbides, metal silicates, metal borides, metal nitrides and ceramics.

4. The coating for spraying as claimed in claim 3, wherein the plurality of particles comprises carbon particles coated with a metal having a melting point less than or equal to 1000°C.

5. The coating for spraying as claimed in claim 1, wherein the plurality of particles comprise materials selected from the group consisting of aluminum and ceramics.

6. The coating for spraying as claimed in claim 1, wherein at least a portion of the material is embedded below the surface of the substrate.

7. The coating for spraying as claimed in claim 6, wherein the carbon-metal composite material portion embedded below the surface of the substrate provides adhesion between the deposited layer and the substrate.

8. A method for depositing a carbon-metal composite material as a coating, the method comprising: spraying a deposited layer of a material onto or within a substrate or forming a surface of a substrate; and embedding at least a portion of the carbon-metal composite material within the substrate, the carbon-metal composite material comprising a plurality of particles, at least a portion of the plurality of particles having metallic bonds and at least a portion of the plurality of particles having covalent bonds.

9. The method of claim 8, wherein the plurality of particles comprises materials selected from the group consisting of: carbon allotropes, ZnO, SiO, SiC, AlC, FeSi, and NiO.

10. The method of claim 8, wherein the plurality of particles comprises materials selected from the group consisting of: carbon, sulfur, silicon, iron, nickel, manganese, metal oxides, metal carbides, metal silicates, metal borides, metal nitrides, and ceramics.

11. The method of claim 10, wherein the plurality of particles comprises carbon particles coated with a metal having a melting point less than or equal to 1000°C.

12. The method of claim 8, wherein the plurality of particles comprises materials selected from the group consisting of aluminum and ceramics.

13. The method of claim 8, wherein at least a portion of the material is embedded below the surface of the substrate.

14. The method of claim 13, wherein the carbon-metal composite portion embedded below the surface of the substrate provides adhesion between the deposited layer and the substrate.

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