1322 results about "Ferroics" patented technology

A method and system for providing a magnetic element capable of being written using spin-transfer effect while being thermally stable and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a first, second and third pinned layers, first and second nonmagnetic layers, a free layer and a nonmagnetic spacer layers. The first, second and third pinned layers are ferromagnetic and have first, second and third magnetizations pinned in first, second and third directions. The first and second nonmagnetic layers include first and second diffusion barriers, respectively. The first and second nonmagnetic layers are between the first and second pinned layers and the second and third pinned layers, respectively. The first and second pinned layers and the second and third pinned layers are antiferromagnetically coupled. The nonmagnetic spacer layer is conductive and resides between the free layer and the third pinned layer. In addition, performance can be further improved by doping Co containing ferromagnetic layers with Cr and / or Pt.

A method and apparatus for providing information from a speed and direction sensor is disclosed. The method and apparatus detect the presence of a ferromagnetic object as it moves past a sensor. The sensor determines speed and direction information regarding the ferromagnetic object, and further provides information relating to the environment surrounding the sensor or object, such as the status of an air gap between the sensor and the moving object, and the temperature of the environment in which the sensor or object is disposed.

Certain embodiments provide a system including a heater. The heater includes one or more electrical conductors. The heater is configured to generate a heat output during application of electrical current to the heater. The heater includes a ferromagnetic material. A conduit at least partially surrounds the heater. A fluid is located in a space between the heater and the conduit. The fluid has a higher thermal conductivity than air at standard temperature and pressure (STP) (0° C. and 101.325 kPa). The system is configured to provide (a) a first heat output below a selected temperature when time-varying electrical current is applied to the heater, and (b) a second heat output near or above the selected temperature when time-varying electrical current is applied to the heater.

The invention relates to an improved method for the manufacture of magnetically responsive particles, also called ferrofluids. The improved method involves a heat treatment step, which may occur at various times during the preparation of the materials, including during subdivision of the magnetic starting material, during the addion of a coating material, after formation of a magnetically responsive particle, or some combination thereof. The materials formed by such a process have numerous advantages over materials formed by other processes, including enhanced salt stability, increased coating uptake, and increased binding capacity. These ferrofluids have applications in a variety of preparative and diagnostic techniques, including immunoassay, cell separations, toxicity testing, food testing, environmental analysis, and MRI.

Each layer in the magnetic multilayer film is a closed ring or oval ring and the magnetic moment or flux of the ferromagnetic film in the magnetic unit is in close state either clockwise or counterclockwise. A metal core is put in the geometry center position in the close-shaped magnetic multilayer film. The cross section of the metal core is a corresponding circular or oval. A MRAM is made of the closed magnetic multilayer film with or without a metal core. The close-shaped magnetic multilayer film is formed by micro process method. The close-shaped magnetic multilayer film can be used broadly in a great variety of device that uses a magnetic multilayer film as the core, such as MRAM, magnetic bead in computer, magnetic sensitive sensor, magnetic logic device and spin transistor.

The present invention relates to perpendicular magnetic recording media with improved signal-to-medium noise ratio (“SMNR”) and thermal stability, which media include a pair of vertically spaced-apart perpendicular ferromagnetic layers which are anti-ferromagnetically coupled (“AFC”) across a non-magnetic spacer layer. The invention is of particular utility in the fabrication of data / information storage and retrieval media, e.g., hard disks, having ultra-high areal recording / storage densities.

The invention provides an electric pressure cooker capable of automatically exhausting. The electric pressure cooker comprises a cooker body, a cooker cover and a control circuit, wherein an exhaust pipe and a gravity hammer which is in sealed contact with the exhaust pipe are arranged on the cooker cover; a first connecting rod is additionally arranged on the cooker cover; a ferromagnetic material is arranged at the first end of the first connecting rod; the position, corresponding to the ferromagnetic material, of the cooker body, is provided with an electromagnet which can take a magnetic effect on the ferromagnetic material; the electromagnetic is electrically connected to the control circuit; the second end of the first connecting rod is in transmitted connection to the gravity hammer; and the gravity hammer is displaced directly or indirectly when the second end of the first connecting rod displaces upwards, and the gravity hammer is separated away from the port of the exhaust pipe. By virtue of the electromagnet and a lever linkage device which are mutually matched, the electric pressure cooker can simplify an automatically exhausting structure, shorten a power transmission route, reduce a probability of a jamming phenomenon in a power transmission process and improve product quality.

A layered ferromagnetic structure is composed of a first ferromagnetic layer positioned over a substrate; a second ferromagnetic layer positioned over the first ferromagnetic layer; and a first non-magnetic layer placed between the first and second ferromagnetic layers. The top surface of the first ferromagnetic layer is in contact with the first non-magnetic layer. The first ferromagnetic layer includes a first orientation control buffer that exhibits an effect of enhancing crystalline orientation of a film formed thereon.

A magnetic field measurement system can include at least one magnetometer; and a ferrofluid shield disposed at least partially around the at least one magnetometer. For example, the ferrofluid shield can include a microfluid fabric and a ferrofluid disposed in or flowable into the microfluid fabric. As another example, the ferrofluid shield can include a ferrofluid and a controller configured to alter an arrangement of the ferrofluid within the ferrofluid shield.

A device includes a liquid metal and a ferrofluid contained in a closed tube. Many electrode groups are connected to the closed tube. A feedback device is connected to the electrode groups. The feedback device switches power to each electrode group in series to circulate the liquid metal and move the ferrofluid in the closed tube.

An ambient electromagnetic energy collector has a magnetic core of high permeability ferromagnetic material wrapped in an inductor coil for coupling primarily to a magnetic field component of a propagating transverse electromagnetic (TEM) wave. For coupling to electromagnetic waves of a wide range of frequencies and magnitudes, the collector is coupled to a multi-phase transformer connected to a multi-phase diode voltage multiplier to provide a current source output to an associated energy storage device. An output controller supplies output power as needed to the associated energy-using device. Preferred types of ferromagnetic materials include nickel-iron alloys with a small percentage of silicon, molybdenum, or copper. It may be combined with other types of ambient energy collectors, such as acoustic / vibration, thermoelectric, and photovoltaic collectors, in a multi-source device provided with a collector interface for converting the different outputs for storage in a common energy storage device. The multi-source ambient energy collector device can be used to supply power to embedded devices, remotely deployed wireless sensors or RFID tags, and other types of monitoring devices distributed over large areas or in industrial environments.

Current-perpendicular-to-plane (CPP) spin valve (SV) and magnetic tunnel junction (MTJ) sensors are provided having an antiparallel (AP)-coupled longitudinal bias stack for instack biasing to stabilize the free layer. A CPP sensor comprises a longitudinal bias stack adjacent to and in contact with a free (sense) layer of the sensor. The bias stack comprises an antiparallel (AP)-pinned layer including FM1 and FM2 layers separated by an antiparallel coupling (APC) layer. The FM1 layer is separated from the free layer of the sensor by a nonmagnetic spacer layer. By choosing the relative thicknesses of the FM1 and FM2 layers, the bias field HB from the AP-pinned layer and the ferromagnetic coupling field HFC between the FM1 layer and the free layer is made additive at the free layer for either positive or negative coupling. By ensuring that the bias field adds to the coupling field, the stability of the free layer by in-stack longitudinal biasing is improved.

A magnetic data track used in a magnetic shift register memory system may be fabricated by forming a multilayered stack of alternating dielectric and / or silicon layers. Vias of approximately 10 microns tall with a cross-section on the order of 100 nm×100 nm are etched in this multilayered stack of alternating layers. Vias may be etched form smooth or notched walls. Vias are filled by electroplating layers of alternating types of ferromagnetic or ferrimagnetic metals. The alternating ferromagnetic or ferrimagnetic layers are comprised of magnetic materials with different magnetization or magnetic exchange or magnetic anisotropies. These different magnetic characteristics allow the pinning of magnetic domain walls at the boundaries between these layers. Alternatively, vias are filled with a homogeneous ferromagnetic material. Magnetic domain walls are formed by the discontinuity in the ferromagnetic or ferromagnetic material that occurs at the notches or at the protuberances along the via walls.

Thermally adjustable surgical tools include a conductor and a ferromagnetic material. The ferromagnetic material may be quickly heated when subjected to high frequency alternating current through the conductor. The ferromagnetic material may also cool rapidly because of its relatively low mass and the small thermal mass of the conductor. The thermally adjustable surgical tools may be used to sculpt, melt, break and / or remove biological material. The thermally adjustable surgical tools may also include balloon catheters which can heat fluid to thereby treat biological material.

A magnetic memory is composed of: a magnetoresistance element including a free magnetic layer; a first interconnection extending in a first direction obliquely to an easy axis of the free magnetic layer; a second interconnection extending in a second direction substantially orthogonal to the first direction; and a write circuit writing data into the free magnetic layer through developing a first write current on the first interconnection, and then developing a second write current on the second interconnection with the first write current turned on. The free magnetic layer includes: first to N-th ferromagnetic layers and first to (N−1)-th non-magnetic layers with N being equal to or more than 4, the i-th non-magnetic layer being disposed between the i-th and (i+1)-th ferromagnetic layers with i being any of natural numbers equal to or less than N−1. The free magnetic layer is designed so that antiferromagnetic coupling(s) between the j-th and (j+1)-th ferromagnetic layers is stronger than that between the first and second ferromagnetic layers, j being any of integers ranging from 2 to N−2.

A patterned perpendicular magnetic recording medium has discrete magnetic islands, each of which has a recording layer (RL) structure that comprises two exchange-coupled ferromagnetic layers. The RL structure may be an “exchange-spring” RL structure with an upper ferromagnetic layer (MAG2), sometimes called the exchange-spring layer (ESL), ferromagnetically coupled to a lower ferromagnetic layer (MAG1), sometimes called the media layer (ML). The RL structure may also include a coupling layer (CL) between MAG1 and MAG2 that permits ferromagnetic coupling. The interlayer exchange coupling between MAG1 and MAG2 may be optimized, in part, by adjusting the materials and thickness of the CL. The RL structure may also include a ferromagnetic lateral coupling layer (LCL) that is in contact with at least one of MAG1 and MAG2 for mediating intergranular exchange coupling in the ferromagnetic layer or layers with which it is in contact (MAG2 or MAG1). The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy with which it is in contact (MAG2 or MAG1).

In a ferromagnetic material containing at least one kind of rare-earth element, a layer containing at least one kind of alkaline earth element or rare-earth element and fluorine is formed at the grain boundary or near the powder surface of the ferromagnetic material. A further layer containing at least one kind of rare-earth element, having a fluorine concentration lower than that of the layer described first and having a rare-earth element concentration higher than that of the host phase of the ferromagnetic material, or an oxide layer containing a rare-earth element is formed in adjacent with a portion of the layer described first.

The invention discloses a method for rapidly detecting ferromagnetic grain content in lubricating oil and a detection device thereof as well as a signal processing circuit. A transformer type electromagnetic sensor is adopted, and variation of related parameters of the electromagnetic sensor which is caused by variation of field distribution due to ferromagnetic grain in lubricating oil is detected, so as to detect ferromagnetic substance content in lubricating oil. Influence of nonferromagnetic pollutant can be naturally eliminated, higher linearity can be realized, meanwhile cost is low, and real time property is good.

The heat resistance of a magnetic resistance device utilizing the TMR effect is improved. Also, the Neel effect of the magnetic resistance device utilizing the TMR effect is restrained. The magnetic resistance device includes a first ferromagnetic layer formed of ferromagnetic material, a non-magnetic insulative tunnel barrier layer coupled to the first ferromagnetic layer, a second ferromagnetic layer formed of ferromagnetic material and coupled to the tunnel barrier layer, and an anti-ferromagnetic layer formed of anti-ferromagnetic material. The second ferromagnetic layer is provided between the tunnel barrier layer and the anti-ferromagnetic layer. A perpendicular line from an optional position of the surface of the second ferromagnetic layer passes through at least two of the crystal grains of the second ferromagnetic layer.

Method and apparatus for providing harmonic inductive power, and more particularly for delivering current pulses providing a desired amount of pulse energy in high frequency harmonics to a load circuit for inductive heating of an article. By controlling the shape and / or frequency of such current pulses, the apparatus and method can be used to enhance the rate, intensity and / or power of inductive heating delivered by the heater coil and / or to enhance the lifetime or reduce the cost and complexity of an inductive heating power supply. Of particular significance, the apparatus and method may be used to significantly increase the power inductively delivered to a ferromagnetic or other inductively heated load, without requiring an increase of current in the heater coil. This enables new heating applications, and in some known applications, decreases the energy consumption or cooling requirements and / or increase the lifetime of the heater coil.

The present invention concerns a new ferromagnetic powder composition comprising soft magnetic iron-based core particles wherein the surface of the core particles are surrounded by an insulating inorganic coating, and a lubricating amount of a compound selected from the group consisting of silanes, titanates, aluminates, zirconates, or mixtures thereof. The invention also concerns a process for the preparation of soft magnetic composite materials using the new powder composition.

A ferrofluid seal incorporates a metal seal comprised of two knife-edges and a flat metal washer is formed between a pole piece and the housing at the axial interface between the parts. One knife edge is machined into the inner face of the housing flange and the other knife edge is machined into the opposing pole piece face. This metal seal effectively seals the pole piece to the housing with a seal suitable for ultra high vacuum applications.

Disclosed in this invention is a family of ternary and multi-nary iron-based new compositions of bulk metallic glasses which possess promising soft magnetic properties, and the composition selection rules that lead to the design of such new compositions. The embodiment alloys are represented by the formula MaXbZc, where M represents at least one of ferromagnetic elements such as iron and may partly be replaced by some other substitute elements; X is an element or combinations of elements selected from those with atomic radius at least 130% that of iron and in the mean time is able to form an M-rich eutectic; and Z is an element or combinations of elements selected from semi-metallic or non-metallic elements with atomic radius smaller than 86% that of iron and in the meantime is able to form an M-Z eutectic; a, b, c are the atomic percentage of M, X, Z, respectively, and a+b+c=100%. When 1%<b<15% and 10%<c<39%, the alloys show a bulk glass forming ability to cast amorphous ribbons / sheets at least 0.1 mm in thickness. When 3%<b<10% and 18%<c<30%, the alloys show a bulk glass forming ability to cast amorphous rods at least 1 mm in diameter. The amorphous phase of these as-cast sheets / rods is at least 95% by volume. This invention also discloses the existence of nano-crystalline phase outside of the outer regime of the bulk glass forming region mentioned above.

A magnetic recording medium has a non-magnetic under-layer, a magnetic layer, a protective film and a liquid lubricant layer sequentially laminated on a non-magnetic substrate. The magnetic layer has a multi-layer structure laminated with two or more magnetic layer components, each of the magnetic layer components having ferromagnetic grains and non-magnetic grain boundaries surrounding the grain. The resulting magnetic recording medium has a granular magnetic layer exhibiting very high Hc accompanying high density of magnetic recording, while decreasing the amount of platinum needed for attaining the high Hc, and reducing media noise accompanying the high recording density.

A carrier is sized and configured for placement in or on a tissue region. The carrier includes at least one interior compartment. At least one ferromagnetic material is carried within the compartment. The compartment and the ferromagnetic material are mutually sized and configured to allow movement of the ferromagnetic material within the compartment in response to magnetic interaction with a magnetic material located outside the carrier. The magnetic interaction can include either a magnetic attracting force or a magnetic repelling force. The carrier can be used in association with a source of magnetism sized and configured for placement in or on a tissue region outside the carrier for magnetic interaction with the ferromagnetic material carried within the compartment, e.g., to stabilize the orientation of a tissue region within an airway.

A positive magnetostrictive material such as a ferromagnetic alloy is subjected to a magnetic field during annealing treatment while being heated for a predetermined period of time at an elevated temperature below its softening temperature followed by cooling resulting in a treated ferromagnetic material having high tensile strength and positive magnetostriction properties for enhancing use thereof under tensile loading conditions. Such treatment of the ferromagnetic alloy may be augmented by application thereto of a compressive stress.