A system for the synthesis of pure bismuth ferrite (BiFeO3)-calcium titanate (CaTiO3) mixed-solution ceramics

Abstract

A system for the synthesis of pure bismuth ferrite calcium titanate mixed-solution ceramics, comprising: a) a mixing unit configured to homogenize stoichiometric amounts of bismuth oxide (Bi2O3), iron oxide (Fe2O3), calcium carbonate (CaCO3) and titanium dioxide (TiO2) with sodium chloride (NaCl) as flux in a weight ratio of 1:3 between the total oxide precursors and salt; b) a calcination unit configured to heat the homogenized mixture at 700°C for 2 hours; c) a cleaning system configured to wash calcined powders with deionized water to remove residual salts; d) a compaction unit configured to operate under a uniaxial pressure of 220 kg / cm² 2 at room temperature forms disc-shaped pellets; e) a sintering plant configured to sinter the pellets at 750 °C for 2 hours with controlled heating and cooling rates of 3 °C / min; and f) an electrode coating unit configured to apply silver paste to the pellet surfaces and allow them to dry for 30 minutes at 70°C.

Description

AREA OF INVENTION

[0001] The present disclosure relates to a system for the synthesis of pure bismuth ferrite (BiFeO3) - calcium titanate (CaTiO3) mixed crystal ceramics, especially at lower concentrations of CaTiO3, as a promising solution for capacitors and MRAM storage devices. BACKGROUND OF THE INVENTION

[0002] Multiferroic materials have attracted considerable interest due to their fascinating physical phenomena and potential applications in various components such as data storage, spintronics, energy harvesting, sensors, and transducers. Bismuth ferrite (BiFeO3, BFO) is a classic multiferroic compound that exhibits electrical and magnetic order coupling at 300 K, a distorted rhombohedral structure, and a high Curie temperature (TC). c ~ 830 °C) and an antiferromagnetic Neel G-type temperature (T NBFO exhibits a temperature range of approximately 370 °C. However, BFO is associated with high leakage current density, high dielectric losses, low remanent polarization, and the difficulty of obtaining the pure phase of this material, which limits its practical application. Metastable phases such as Bi₂Fe₄O₉, Bi₂Fe₄O₉, and Bi₂Fe₄O₉ are examples of such phases. 46 Fe2O 72 and Bi 23 FeO 39 They typically form during production, which makes obtaining the pure phase very difficult.

[0003] To overcome these limitations, calcium titanate (CaTiO 3, CTO), a lead-free material with high dielectric strength, structural stability and resistive dielectric perovskite over a wide temperature range, can be combined with BFO to form a solid solution.

[0004] The BFO-CTO solid solution series is characterized by superior structural stability and functionality, based on improved phase compatibility and targeted defect modulation. The integration of CaTiO3 reduces lattice distortion and the formation of oxygen vacancies, thereby reducing leakage currents by two orders of magnitude. The solid solution series with CTO enables the structural transition from the rhombohedral to the orthorhombic phase and influences the physical properties of the bismuth ferrite material. This material exhibits a high dielectric constant and improved multiferroic properties compared to BFO, making it suitable for applications in capacitors and magnetic random-access memory (MRAM) devices. SUMMARY OF THE INVENTION

[0005] The present invention relates to a system for the synthesis of pure bismuth ferrite calcium titanate (BiFeO3-CaTiO3) mixed-crystal ceramics by means of a flux-assisted preparation process using sodium chloride as the flux. The system enables the low-temperature synthesis of multiferroic ceramic materials with improved dielectric and magnetic properties through controlled mixing, calcination, purification, compaction, sintering, and electrode coating units. It facilitates the production of mixed crystals of the general chemical formula (1-x)BiFeO3-xCaTiO3, where x varies from 0.1 to 0.4, and includes a characterization device for analyzing the structural, morphological, and functional properties of the synthesized ceramics, which are suitable for applications in capacitors and MRAM memory devices.

[0006] The present disclosure relates to a system for the synthesis of pure bismuth ferrite (BiFeO3)-calcium titanate (CaTiO3) mixed-crystal ceramics. The system comprises: a) a mixing unit for homogenizing stoichiometric amounts of bismuth oxide (Bi2O3), iron oxide (Fe2O3), calcium carbonate (CaCO3), and titanium dioxide (TiO2) with sodium chloride (NaCl) as a flux in a weight ratio of 1:3 between the total oxide precursors and the salt; b) a calcination unit for heating the homogenized mixture at 700°C for 2 hours; c) a purification unit for washing the calcined powders with deionized water to remove residual salts; d) a compaction unit for producing disc-shaped pellets under a uniaxial pressure of 220 kg / cm². 2at room temperature; e) a sintering plant configured to sinter the pellets at 750°C for 2 hours with controlled heating and cooling rates of 3°C / min; and f) an electrode coating plant configured to apply silver paste to the pellet surfaces and dry at 70°C for 30 minutes.

[0007] The aim of the present disclosure is to provide a system for the synthesis of pure bismuth ferrite (BiFeO3) - calcium titanate (CaTiO3) mixed crystal ceramics.

[0008] Another objective of the present disclosure is the synthesis of pure bismuth ferrite-calcium titanate mixed-solution ceramics by means of a low-temperature NaCl-based melting salt process, which ensures phase purity while simultaneously controlling grain growth and the volatilization of Bi 3+ minimized

[0009] Another objective of the present disclosure is the production of multiferroic ceramics with improved dielectric properties, exhibiting a higher dielectric constant and a low loss factor, as well as improved magnetic properties with saturated hysteresis loops.

[0010] Another objective of the present disclosure is the production of a silver-coated electrode, wherein a pellet made from prepared powder of bismuth ferrite (BiFeO3) - calcium titanate (CaTiO3) is coated with silver paste to serve as an electrode.

[0011] Another objective of the present disclosure is the characterization of the synthesized mixed-crystal ceramics for the analysis of their structural properties, surface morphology, element distribution, valence states, dielectric properties and magnetic hysteresis loops.

[0012] To further clarify the advantages and features of the present disclosure, the invention is described in more detail with reference to specific embodiments illustrated in the accompanying drawings. It is understood that these drawings merely show typical embodiments of the invention and are therefore not to be understood as limiting its scope of protection. The invention is described and explained in more detail and with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE IMAGES

[0013] These and other features, aspects and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which identical symbols represent identical parts, wherein: Fig. Figure 1 shows a block diagram of a system for the synthesis of pure bismuth ferrite (BiFeO3) - calcium titanate (CaTiO3) mixed crystal ceramics according to an embodiment of the present disclosure; Fig. Figure 2 shows (i) the XRD pattern and (ii) an enlarged view of the Bragg peaks of BFO-CTO mixed crystal pellets in the range 0.1 ≤ x ≤ 0.4 according to an embodiment of the present disclosure; Fig. Figure 3 shows a table with the structural parameters of the BFO-CTO mixed-solution ceramic samples obtained by Rietveld refinement analysis according to an embodiment of the present disclosure; and Fig. Figure 4 shows a table with the Rietveld refinement parameters for 0.9BFO-0.1CTO and 0.6BFO-0.4CTO ceramics according to an embodiment of the present disclosure.

[0014] Furthermore, those skilled in the art will recognize that the elements in the drawings are simplified and not necessarily to scale. For example, the flowcharts illustrate the process by highlighting the main steps to facilitate understanding of this disclosure. With regard to the construction of the device, one or more components may be represented in the drawings by conventional symbols. The drawings may show only those specific details relevant to understanding the embodiments of this disclosure, so as not to clutter the drawings with details that are already apparent to those skilled in the art from the description contained herein. DETAILED DESCRIPTION:

[0015] To facilitate understanding of the principles of the invention, reference is made below to the embodiment illustrated in the drawings, which is described using specific terms. It is understood, however, that this does not limit the scope of protection of the invention. Rather, modifications and further developments of the illustrated system, as well as further applications of the inventive principles depicted therein, are conceivable, insofar as they would typically occur to a person skilled in the art in the field of the invention.

[0016] It will be clear to those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not to be understood as a limitation thereof.

[0017] References to “an aspect”, “another aspect”, or similar phrases in this description mean that a particular feature, structure, or property described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, phrases such as “in one embodiment”, “in another embodiment”, and similar expressions in this description may, but do not necessarily, all refer to the same embodiment.

[0018] The terms "includes," "comprehensive," or similar expressions denote non-exclusive inclusion. Thus, a procedure or method containing a list of steps does not only include those steps but may also include further steps not explicitly listed or inherent in the procedure or method. Likewise, the statement "includes..." for one or more devices, subsystems, elements, structures, or components, without further limitations, does not preclude the existence of other devices, subsystems, elements, structures, or components.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meanings generally known to those skilled in the art in the field to which this invention belongs. The systems, methods, and examples described herein serve only for illustration and are not to be understood as limiting.

[0020] The various forms of implementation of the present disclosure are described in detail below with reference to the attached drawings.

[0021] Fig. Figure 1 shows a block diagram of a system (100) for the synthesis of pure bismuth ferrite (BiFeO3) - calcium titanate (CaTiO3) mixed crystal ceramics according to an embodiment of the present disclosure.

[0022] The system (100) according to Fig. 1 comprises: a) a mixing unit (102) for homogenizing stoichiometric amounts of bismuth oxide (Bi2O3), iron oxide (Fe2O3), calcium carbonate (CaCO3), and titanium dioxide (TiO2) with sodium chloride (NaCl) as a flux in a weight ratio of 1:3 between the total oxide precursors and the salt; b) a calcination unit (104) for heating the homogenized mixture at 700 °C for 2 hours; c) a purification unit (106) for washing the calcined powders with deionized water to remove residual salts; d) a compaction unit (108) for forming disc-shaped pellets under a uniaxial pressure of 220 kg / cm² 2 at room temperature; e) a sintering unit (110) configured to sinter the pellets at 750°C for 2 hours with controlled heating and cooling rates of 3°C / min; and f) an electrode coating unit (112) configured to apply silver paste to the pellet surfaces and dry at 70°C for 30 minutes.

[0023] In one embodiment, the system is configured to synthesize solid solutions with the general chemical formula (1- x) BiFeO3 - x CaTiO3, where x varies from 0.1 to 0.4.

[0024] In one embodiment, the mixing unit (102) is configured to grind the mixture for approximately 3 hours to ensure uniform mixing and homogeneity at the molecular level.

[0025] In one embodiment, the calcining unit (104) and the sintering unit (110) comprise aluminium oxide crucibles for receiving the powder mixture during the heating processes.

[0026] In one embodiment, the cleaning unit (106) further comprises a test device configured to perform a qualitative titration test with silver nitrate (AgNO3) to confirm the complete elimination of chloride ions.

[0027] In one embodiment, the compression unit (108) is configured to produce pellets with an approximate thickness of 1 mm and a diameter of 10 mm.

[0028] In one embodiment, the system (100) further comprises a drying unit (114) configured to dry purified powders at 80°C for 12 hours.

[0029] In one embodiment, the system (100) further comprises a characterization unit (116) for analyzing the synthesized ceramics, wherein the characterization unit (116) comprises: an X-ray diffraction instrument for structural analysis; a field emission scanning electron microscope with EDX for analyzing the surface morphology and element distribution; an X-ray photoelectron spectrometer for determining the valence state; and a dielectric measuring instrument and a vibration sample magnetometer for analyzing the electrical and magnetic properties.

[0030] In one embodiment, the dielectric measuring device is configured to operate at 300 K in the frequency range of 100 Hz to 1 MHz with a signal strength of 1 Vrms.

[0031] In one embodiment, the vibration probe magnetometer is configured to measure magnetic hysteresis loops by applying a magnetic field of ±10 kOe.

[0032] The present invention relates to a system for the synthesis of mixed crystals from (1- x) BFO - x CTO (0.1 ≤ x ≤ 0.4) ceramics by means of a NaCl-based melting salt synthesis at low temperature.

[0033] In the present system, high-purity raw materials such as bismuth oxide (Bi₂O₃), iron oxide (Fe₂O₃), calcium carbonate (CaCO₃), and titanium dioxide (TiO₂) are used as starting materials for the synthesis of a series of mixed crystals with the general chemical formula (1-x)BiFeO₃-xCaTiO₃, where x varies from 0.1 to 0.4. The selected compositions, in particular x = 0.1, 0.2, 0.3, and 0.4, are prepared by melting salt synthesis in the stoichiometric molar ratio of the respective oxides.

[0034] The mixing unit is configured to accept sodium chloride (NaCl) as a flux to accelerate the reaction kinetics and to maintain a weight ratio of 1:3 between the total oxide precursors and the salt. The mixing unit consists of an agate mortar in which the entire mixture is thoroughly ground for approximately 3 hours to ensure uniform mixing and homogeneity at the molecular level. NaCl was selected based on the following considerations: (i) NaCl has a relatively low melting point (~801 °C), allowing the reaction to proceed at lower synthesis temperatures compared to traditional solid-state methods. This helps maintain phase purity while minimizing grain growth and Bi volatilization. 3+(ii) NaCl is chemically inert towards the precursor oxides (Bi₂O₃, Fe₂O₃, CaCO₃, TiO₂) and does not participate in the formation of secondary phases. This ensures clean reaction pathways and easy removal after synthesis by washing. Furthermore, NaCl forms eutectic mixtures with KCl or other alkali halides as required, thus providing additional flexibility. NaCl is preferred over other fluxes such as KCl, LiCl, or Na₂CO₃ because these often exhibit higher reactivity or hygroscopicity, or lead to incomplete removal after synthesis. NaCl, on the other hand, offers a good balance between reactivity control, ease of removal, and product yield.

[0035] After homogenization, the powder mixture is placed in high-purity aluminum oxide crucibles in the calcination unit and calcined in a muffle furnace at 700 °C for 2 hours. The purification unit repeatedly washes the calcined powders with deionized water to effectively remove residual salts. It also includes a test device for performing a qualitative titration with silver nitrate (AgNO3) to confirm the complete removal of chlorides by the absence of precipitation. After filtration, the purified powders are dried in the drying unit for 12 hours on a hot plate at 80 °C.

[0036] The compaction unit compresses the dried powders using a hydraulic press under a uniaxial pressure of 220 kg / cm². 2At room temperature, the raw material is processed into disc-shaped pellets approximately 1 mm thick and 10 mm in diameter. The sintering unit then sinters the pellets for 2 hours at 750 °C with controlled heating and cooling rates of 3 °C / min to obtain high-density ceramic and promote grain growth. The electrode coating unit coats both sides of each pellet with silver paste, which acts as electrodes. The pellets are then dried for 30 minutes at 70 °C on a hot plate to ensure optimal adhesion and conductivity. The sintered ceramic samples, which belong to the composition series (1- x) BiFeO3 - x CaTiO3 (x = 0.1, 0.2, 0.3, and 0.4), are designated as 0.9BFO-0.1CTO, 0.8BFO-0.2CTO, 0.7BFO-0.3CTO, and 0.6BFO-0.4CTO, respectively.

[0037] The characterization unit includes an X-ray diffractometer, specifically a Rigaku Ultima-IV diffractometer with Cu-Kα radiation, configured to analyze the structure of synthesized polycrystalline ceramic samples. The X-ray diffractometer is configured to record powder X-ray diffractograms (XRD) in the 20° range from 20° to 70° at a scan rate of 2° / min and a step size of 0.02°. The characterization unit also includes a field emission scanning electron microscope (FESEM, FEI Apero). Furthermore, the unit comprises a LoVac system with an associated EDX instrument for investigating the surface morphology and elemental distribution of the samples using elemental mapping analysis. Additionally, a Thermo Fisher X-ray photoelectron spectrometer (K-alpha) is available for determining the valence states of the constituents of the sintered samples.The dielectric measuring device consists of a Wayne Kerr LCR meter, which performs dielectric measurements at 300 K in the frequency range of 100 Hz to 1 MHz with a typical signal strength of 1 V. eff A vibration magnetometer (VSM, Lakeshore 7400) is used to measure the magnetic hysteresis loop (MH loop) of the sintered samples at room temperature by applying a magnetic field of ±10 kOe.

[0038] Fig. Figure 2 shows (i) the XRD pattern and (ii) an enlarged view of the Bragg peaks of BFO-CTO mixed crystal pellets in the range 0.1 ≤ x ≤ 0.4 according to an embodiment of the present disclosure;

[0039] At lower CTO concentrations, the XRD spectra showed a distorted rhombohedral perovskite structure of the pure BFO phase. With increasing CTO content, the diffraction peaks (1 0 4) and (1 1 0) merged, as shown in Fig. Figure 2 shows FESEM images of these BFO substitution ceramics exhibiting a uniform, granular morphology. Interestingly, the 0.6BFO-0.4CTO composition showed a higher dielectric constant (~162) and a lower loss factor (~0.09) at 300 K. The MH hysteresis curves showed saturated loops for all samples. The 0.8BFO-0.2CTO composition achieved a 2M s The value of ~8.4 emu / g is attributed to increased spin tilt due to the higher surface-to-volume ratio of the BFO nanoparticles. These findings provided insights into the phenomenon of structure-property correlation and make BFO-CTO solid-state solutions promising for applications in capacitors and MRAM memory devices.

[0040] Fig. Figure 3 shows a table with the structural parameters of the BFO-CTO mixed-solution ceramic samples obtained by Rietveld refinement analysis according to an embodiment of the present disclosure; and

[0041] Fig. Figure 4 shows a table with the Rietveld refinement parameters for 0.9BFO-0.1CTO and 0.6BFO-0.4CTO ceramics according to an embodiment of the present disclosure.

[0042] The characterization unit is further configured to perform Rietveld refinement on all prepared sintered compositions (x = 0.1, 0.2, 0.3, and 0.4) to investigate the structural characterization of the (1-x)BiFeO3-xCaTiO3 solid solution system. The system is configured to simulate the XRD background using the linear interpolation method, while the pseudo-Voigt function is used to optimize the diffraction peaks and peak distribution. The obtained lattice parameters and the unit cell volume of all investigated samples are shown in the table in Fig. listed.

[0043] The results show that the lattice parameters and unit cell volume of BFO-CTO solid solution samples gradually decrease with increasing CTO concentration. In contrast, a slight increase in lattice parameters and unit cell volume is observed at 0.6BFO-0.4CTO. This anomaly is attributed to a possible structural transition near x = 0.4, where the solid solution system likely undergoes a transition from a rhombohedral to an orthorhombic structure. The XRD pattern ( Fig. 2) shows that the structural transition at x = 0.4 is more of a gradual, composition-dependent transformation than an abrupt or complete phase transition. The Rietveld refinement, particularly at x = 0.4, exhibits overlapping features characteristic of both rhombohedral (R3c) and orthorhombic (Pbnm) symmetry, suggesting the coexistence of both phases. The results show that the replacement of Bi 3+ - and Fe 3+ -ions through smaller Ca 2+ - and Ti 4+The presence of ions in the BFO lattice leads to reduced lattice parameters and a smaller unit cell volume due to ion size effects and induced lattice distortion. Simultaneously, at x = 0.4, the higher concentration of CaTiO3 is crucial for stress relaxation and the reconfiguration of the crystal lattice. These structural changes, such as modifications to the octahedral tilt and bond angles, along with a possible solubility limit effect, contribute to the increased lattice parameters and the larger unit cell volume for composition x = 0.4. To correlate the physical properties, the system was configured such that bond angles, bond lengths, and the other Rietveld refinement parameters were determined for the specific compositions 0.9BFO-0.1CTO and 0.6BFO-0.4CTO (see table in [reference]). Fig. 4) were determined.

[0044] In the present invention, pure-phase (1- x)BiFeO3- xCaTiO3-substitutional solid solution ceramics are successfully synthesized using a low-temperature process with NaCl flux. X-ray diffraction analysis confirms a rhombohedral R3c structure up to x = 0.3, followed by a structural transition to the orthorhombic Pbnm structure above this composition. The crystallite sizes, determined by Williamson-Hall analysis, are in the nanometer range of 40-50 nm.

[0045] The incorporation of CTO with smaller ionic radii influences the morphology of BFO ceramics, resulting in more uniform and homogeneous grains, particularly in the 0.6BFO-0.4CTO sample, as observed by field emission scanning electron microscopy (FE-SEM). The mean grain size decreases with increasing CTO content from 1.62 µm to 0.64 µm, indicating lattice distortion due to ion substitution. X-ray photoelectron spectroscopy (XPS) confirms the presence of multivalent Fe ions and supports hopping and double-exchange mechanisms contributing to the ferromagnetic behavior. Dielectric measurements were taken to investigate the dielectric constant and loss factor (tan δ) of all compositions in the frequency range from 10 Hz to 1 MHz. The dielectric behavior was explained using Maxwell-Wagner polarization and the Koop two-layer model.Replacing BFO with CTO alters the crystal symmetry and significantly increases the dielectric constant, resulting in a low dielectric loss factor for the BFO ceramic. Measurements of magnetic hysteresis at room temperature using a vibrating magnetometer show a saturation loop with a maximum magnetization of approximately 8.4 emu / g for the 0.8 BFO-0.2 CTO sample. The increased CTO content disrupts the cycloidal spin structure of BFO, leading to altered magnetic properties. This confirms that incorporating CTO into the BFO matrix not only stabilizes the structure but also improves the dielectric and magnetic properties. Therefore, these ceramics are promising for multifunctional applications.

[0046] The drawings and the preceding description illustrate embodiments. Those skilled in the art will recognize that one or more of the described elements can be combined to form a single functional element. Alternatively, certain elements can be divided into several functional elements. Elements of one embodiment can be added to another. For example, the process flows described here can be modified and are not limited to the manner described herein. Furthermore, the actions of a flowchart need not be performed in the sequence shown; nor do all actions necessarily need to be carried out. Actions that do not depend on other actions can be performed in parallel with the other actions. The scope of protection of the embodiments is in no way limited by these specific examples. Numerous variations, whether explicitly stated in the description or not, such as...Differences in structure, dimensions, and materials are possible. The scope of protection of the embodiments is at least as comprehensive as described by the following claims.

[0047] The advantages, other benefits, and problem solutions have been described above with reference to specific embodiments. However, the advantages, benefits, problem solutions, and any components that can effect or enhance an advantage, benefit, or solution are not to be construed as critical, necessary, or essential features or components of the claims. REFERENCES 100 A system for the synthesis of pure bismuth ferrite (BiFeO3)-calcium titanate (CaTiO3) mixed crystal ceramics. 102 Mixing unit 104 calcination units 106 cleaning units 108 compaction units 110 sintering plant 112 Electrode coating unit 114 drying unit 116 Characterization Unit

Claims

[1] A system for the synthesis of pure bismuth ferrite calcium titanate mixed-solution ceramics, comprising: a) a mixing unit configured to homogenize stoichiometric amounts of bismuth oxide (Bi2O3), iron oxide (Fe2O3), calcium carbonate (CaCO3) and titanium dioxide (TiO2) with sodium chloride (NaCl) as flux in a weight ratio of 1:3 between the total oxide precursors and salt; b) a calcination unit configured to heat the homogenized mixture at 700°C for 2 hours; c) a cleaning system configured to wash calcined powders with deionized water to remove residual salts; d) a compaction unit configured to operate under a uniaxial pressure of 220 kg / cm² 2 at room temperature forms disc-shaped pellets; e) a sintering plant configured to sinter the pellets at 750 °C for 2 hours with controlled heating and cooling rates of 3 °C / min; and f) an electrode coating unit configured to apply silver paste to the pellet surfaces and allow them to dry for 30 minutes at 70°C. [2] System according to claim 1, wherein the system is configured to synthesize solid solutions with the general chemical formula (1- x)BiFeO3 - x CaTiO3, where x varies from 0.1 to 0.

4. [3] System according to claim 1, wherein the mixing unit is configured to grind the mixture for about 3 hours to ensure uniform mixing and homogeneity at the molecular level. [4] System according to claim 1, wherein the calcining unit and the sintering unit comprise aluminium oxide crucibles for receiving the powder mixture during the heating processes. [5] System according to claim 1, wherein the cleaning unit further comprises a test device configured to perform a qualitative titration test with silver nitrate (AgNO3) to confirm the complete elimination of chloride ions. [6] System according to claim 1, wherein the compression unit is configured to form pellets with an approximate thickness of 1 mm and a diameter of 10 mm. [7] System according to claim 1, further comprising a drying unit designed for drying purified powders at 80°C for 12 hours. [8] System according to claim 1, further comprising a characterization unit for analyzing the synthesized ceramics, wherein the characterization unit comprises: o X-ray diffraction devices for structural analysis; o Field emission scanning electron microscope with EDX resolution for the analysis of surface morphology and element distribution; o X-ray photoelectron spectroscopic instruments for valence state identification; and o Dielectric measuring instruments and vibration magnetometers for the analysis of electrical and magnetic properties. [9] System according to claim 8, wherein the dielectric measuring device is designed for operation at 300 K in the frequency range from 100 Hz to 1 MHz with a signal strength of 1 Vrms. [10] System according to claim 8, wherein the vibration probe magnetometer is configured to measure magnetic hysteresis loops by applying a magnetic field of ±10 kOe.

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