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Phase Equilibria and Magnetic Phases in the Ce-Fe-Co-B System
Tian Wang1, Dmytro Kevorkov2, Mamoun Medraj3,4
1Department of Mechanical and Industrial Engineering, Concordia University, 1455 de Maisonneuve Boulevard West, Montreal, QC H3G 1M8, Canada. wa_ti@encs.concordia.ca.
Materials (Basel, Switzerland)
|August 5, 2017
Summary
This study maps phase equilibria in the Ce-Fe-Co-B system for permanent magnets. Researchers identified key magnetic phases and their compositions, revealing Ce₂(Fe, Co)₁₄B exhibits superior magnetization.
Area of Science:
- Materials Science
- Solid State Chemistry
- Magnetism
Background:
- The Cerium-Iron-Cobalt-Boron (Ce-Fe-Co-B) system is a critical area for developing advanced permanent magnets.
- Understanding phase equilibria is essential for optimizing magnetic properties and material performance.
Purpose of the Study:
- To investigate the phase equilibria within the Ce-Fe-Co-B system at 900 °C.
- To identify and characterize novel magnetic phases and their homogeneity ranges.
- To evaluate the magnetic properties of identified phases using advanced microscopy techniques.
Main Methods:
- Employed a high-throughput screening method utilizing diffusion couples and key alloys.
- Utilized Scanning Electron Microscope/Wavelength Dispersive X-ray Spectroscope (SEM/WDS) for elemental analysis.
- Applied Magnetic Force Microscope (MFM) to assess magnetic interactions and properties.
Main Results:
- Identified three magnetic phases: Ce₂Fe₁₄-ₓCoₓB (0 ≤ x ≤ 4.76), CeCo₄-ₓFeₓB (0 ≤ x ≤ 3.18), and Ce₃Co₁₁-ₓFeₓB₄ (0 ≤ x ≤ 6.66).
- Determined the homogeneity ranges for these magnetic phases at 900 °C.
- MFM analysis indicated Ce₂(Fe, Co)₁₄B possesses stronger magnetization compared to Ce(Co, Fe)₄B and Ce₃(Co, Fe)₁₁B₄.
Conclusions:
- The Ce-Fe-Co-B system exhibits complex phase relationships crucial for permanent magnet development.
- Ce₂(Fe, Co)₁₄B is highlighted as a promising phase for high-performance permanent magnets due to its superior magnetic properties.
- Further research is needed to determine the crystal structure of the observed boron-rich solid solution phase.
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