Mn-Induced Thermal Stability of L1₀ Phase in Fept Magnetic Nanoscale Ribbons

Area of Science:

• Materials Science
• Nanotechnology
• Magnetism

Background:

• L1₀ tetragonal phase magnetic nanoscale materials like FePt are promising rare earth-free permanent magnets.
• High operating temperatures are desired for advanced magnet applications.

Purpose of the Study:

• To synthesize and characterize a Mn-modified FePt alloy for enhanced magnetic properties.
• To investigate the structural stability and phase transformation of the L1₀ phase with Mn addition.

Main Methods:

• Melt-spinning and annealing for material synthesis.
• Proton-induced X-ray emission spectroscopy (PIXE) for composition analysis.
• X-ray diffraction (XRD) with Rietveld analysis and temperature-dependent synchrotron XRD for structural analysis.
• Magnetic hysteresis loop measurements.

Main Results:

• Successful synthesis of Fe₅₇Mn₈Pt₃₅ alloy ribbons with L1₀ phase formation after annealing.
• Mn addition promotes higher ordering and significantly enhances the structural stability of the L1₀ phase up to 800 °C.
• Inhibition of crystal growth and unit cell expansion by Mn addition.
• Observation of a strong coercive field in single-phase L1₀ samples.

Conclusions:

• Mn addition effectively stabilizes the L1₀ phase in FePt-based magnetic materials.
• The enhanced thermal stability makes these materials suitable for high-temperature applications.
• These findings support the development of rare earth-free nanocomposite magnets for extreme conditions.