EVOLUTION OF FERRO ELECTRIC AND FERRO MAGNETIC PROPERTIES OF RARE EARTH ALUMINIUM SUBSTITUTED M-TYPE BARIUM HEXA FERRITES AT ROOM TEMPERATURE
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2020-09-01 |
| Journal | Digest Journal of Nanomaterials and Biostructures |
| Authors | F. SEHAR, S. ANJUM, Zeeshan Mustafa |
| Institutions | Chinese Academy of Sciences, Lahore Garrison University |
| Citations | 1 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: MPCVD Diamond for Advanced Multiferroic Platforms
Section titled âTechnical Documentation & Analysis: MPCVD Diamond for Advanced Multiferroic PlatformsâThis document analyzes the research on rare earth aluminum substituted M-type barium hexa-ferrites (BaAl${x}$Fe${(12-x)}$O$_{19}$) and outlines how 6CCVDâs specialized MPCVD diamond materials and services are critical for advancing this research into functional spintronic and microwave devices.
Executive Summary
Section titled âExecutive SummaryâThe analyzed research confirms the successful synthesis and characterization of room-temperature multiferroic M-type barium hexa-ferrites, a material class highly relevant to next-generation spintronics and magneto-electric applications.
- Multiferroic Confirmation: Clear ferro-electric (P-E) hysteresis loops and strong magnetic properties ($M_s$, $H_c$) were observed simultaneously at room temperature.
- Tunable Properties: Aluminum substitution ($x=0.2$ to $1.2$) provides precise control over magnetic characteristics, decreasing saturation magnetization ($M_s$) while increasing coercivity ($H_c$).
- Optical Relevance: The optical band gap ($E_g$) was shown to increase significantly (up to 4.22 eV) as crystallite size decreased, indicating potential for integrated opto-electronic devices.
- Application Focus: These materials are promising candidates for magneto-electric devices, permanent magnets, and high-frequency microwave applications.
- 6CCVD Value Proposition: 6CCVD supplies the necessary high-purity, high-thermal-conductivity Single Crystal Diamond (SCD) and Polycrystalline Diamond (PCD) substrates required for the integration, thermal management, and high-frequency operation of thin-film multiferroic devices.
- Custom Engineering: We offer custom dimensions (up to 125mm), ultra-low roughness polishing (Ra < 1nm), and specialized metalization schemes (e.g., Ti/Pt/Au electrodes) essential for fabricating functional multiferroic structures.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the characterization of the BaAl${x}$Fe${(12-x)}$O$_{19}$ samples:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Synthesis Temperature | 1100 | °C | Calcination/Heat Treatment |
| Maximum Applied Magnetic Field | 3 | Tesla | VSM Measurement |
| Maximum Saturation Magnetization ($M_s$) | 72.55 | emu/g | Lowest Al concentration ($x=0.2$) |
| Maximum Coercivity ($H_c$) | 2375 | Oe | Highest Al concentration ($x=1.2$) |
| Maximum Remanent Polarization ($P_r$) | 22.5 | ”C/cm2 | Measured from P-E loop |
| Coercive Electric Field ($E_c$) | 14.9 | KV/m | Measured from P-E loop |
| Maximum Optical Band Gap ($E_g$) | 4.22 | eV | Highest Al concentration ($x=1.2$) |
| Minimum Crystallite Size (D$_{p}$) | 51.80 | nm | Along c-axis (114 peak), $x=1.2$ |
| Standard Lattice Constant âaâ (Pure BaFe${12}$O${19}$) | 5.892 | Ă | Hexagonal structure |
| Standard Lattice Constant âcâ (Pure BaFe${12}$O${19}$) | 23.183 | Ă | Hexagonal structure |
Key Methodologies
Section titled âKey MethodologiesâThe M-type barium hexa-ferrites were prepared using a solid-state ceramic (powder metallurgy) method, followed by comprehensive structural, magnetic, and electrical characterization.
- Precursor Preparation: High purity oxides (Fe${2}$O${3}$, BaCo${3}$, Al${2}$O$_{3}$) were mixed in stoichiometric proportions using acetone for homogeneous wet mixing.
- Thermal Processing: The mixed samples were subjected to heat treatment (calcination/sintering) at 1100°C for 2 hours, followed by slow cooling to prevent quenching.
- Structural Confirmation: X-Ray Diffraction (XRD) confirmed the M-type hexagonal structure (JCPDS card 00-051-1867) and was used to calculate lattice constants and crystallite size (using the Debye-Scherrer equation).
- Morphology and Composition: Scanning Electron Microscopy (SEM) confirmed platelet-like morphology and intergranular pores. Energy Dispersive Spectroscopy (EDS) confirmed the elemental composition (Fe, Ba, O, Al).
- Magnetic Characterization: Vibrating Sample Magnetometer (VSM) operating at 3 Tesla was used to measure the M-H loops, determining saturation magnetization ($M_s$) and coercivity ($H_c$).
- Optical Analysis: UV-Visible spectroscopy (300-900 nm) was used, and the Tauc relationship was applied to calculate the indirect optical band gap ($E_g$).
- Ferro-electric Analysis: A ZT-IA measurement system was used to characterize the P-E hysteresis loops, confirming room-temperature ferro-electric behavior.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe development of functional multiferroic devices based on these hexa-ferrites requires advanced substrates and precise fabrication techniques. 6CCVDâs MPCVD diamond materials provide the necessary thermal, electrical, and mechanical foundation to maximize device performance in spintronic and microwave applications.
Applicable Materials for Multiferroic Integration
Section titled âApplicable Materials for Multiferroic IntegrationâThe high thermal conductivity and electrical isolation of diamond are crucial for managing heat generated in high-frequency magnetic devices and ensuring minimal cross-talk in magneto-electric coupling experiments.
| 6CCVD Material | Recommended Grade | Application Relevance |
|---|---|---|
| Single Crystal Diamond (SCD) | Electronic Grade (High Purity) | Ideal substrate for thin-film deposition of BaAl${x}$Fe${(12-x)}$O$_{19}$. Provides superior thermal management for high-power microwave devices. |
| Polycrystalline Diamond (PCD) | Thermal Grade | Cost-effective solution for larger area (up to 125mm wafers) or bulk testing platforms requiring excellent heat spreading. |
| Boron-Doped Diamond (BDD) | Heavy Doping (Metallic) | Can be used as a highly stable, chemically inert electrode or contact layer for electrical measurements, replacing traditional metal contacts in harsh environments. |
Customization Potential for Device Fabrication
Section titled âCustomization Potential for Device FabricationâTo transition from bulk powder studies to integrated thin-film devices, precise material handling and electrode fabrication are essential. 6CCVD offers full customization to meet these engineering demands:
- Custom Dimensions: While the paper used bulk samples, device integration requires specific wafer sizes. 6CCVD provides PCD plates/wafers up to 125mm in diameter and SCD plates with custom dimensions, ensuring compatibility with standard semiconductor processing tools.
- Precision Thickness Control: We offer precise thickness control for both SCD and PCD, ranging from 0.1”m to 500”m for active layers, and substrates up to 10mm for robust thermal platforms.
- Ultra-Low Roughness Polishing: The quality of the interface between the multiferroic film and the substrate is critical. 6CCVD guarantees Ra < 1nm for SCD and Ra < 5nm for inch-size PCD, minimizing scattering losses and improving film adhesion and crystalline quality.
- Integrated Metalization: The P-E loop measurements require robust electrodes. 6CCVD offers in-house custom metalization services, including standard electrode stacks (Au, Pt, Pd, Ti, W, Cu), tailored for specific contact resistance and adhesion requirements on diamond surfaces.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in the material science of diamond and its integration into advanced electronic systems. We offer expert consultation to researchers working on:
- Multiferroic Integration: Assisting with material selection and surface preparation protocols for the heteroepitaxial growth of complex oxides (like M-type ferrites) onto diamond platforms.
- Spintronics and Microwave Applications: Optimizing diamond substrate properties (e.g., nitrogen concentration, surface termination) to enhance the performance and thermal stability of devices utilizing magneto-electric coupling.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The ferro-electric and ferro-magnetic properties of rare earth aluminium substituted Mtype barium hexa-ferrites with the composition of BaAlxFe(12-x)O19 where (x=0.2, 0.4, 0.6, 0.8, 1.0 and 1.2) have been prepared by oxides as precursors employing powder metallurgy route. The structural properties, functional groups, 3-D visualization, elemental analysis, surface morphology, magnetic, optical properties and ferro electric properties of the prepared samples have been characterized through X-Ray Diffractometer (XRD), Fourier Transform Infrared Spectroscopy (FTIR), diamond visualization software, Energy Dispersive Spectroscopy (EDS), Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM), UV-Visible spectroscopy (UV-VIS) and ZT-IA measurement system respectively. The structural measurements depict the confirmation of M-type barium hexa-ferrite structure. EDS spectrum illustrate the elemental composition of the prepared materials for every corresponding âxâ values. The surface morphology shows the existence of platelet like intergranular pores. Magnetic measurements shows that the saturation magnetization (Ms) decreases and coercivity (Hc) increases with increasing aluminium contents. The optical band gap energy increases as the crystallite size decreases. The variation of electric polarization has also been occurred due to the shifting of iron ions in the unit cell structure of oxygen octahedron FeO6.