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Updated: Oct 11, 2025
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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
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Creating a Ferromagnetic Ground State with Tc Above Room Temperature in a Paramagnetic Alloy through Non-Equilibrium
Xinglong Ye1, Nuno Fortunato2, Abhishek Sarkar1,2
1Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344, Eggenstein-Leopoldshafen, Germany.
Advanced Materials (Deerfield Beach, Fla.)
|December 2, 2021
Summary
Researchers created a novel ferromagnetic phase in FeRh alloys using nanostructuring. This breakthrough enables on/off ferromagnetic-paramagnetic switching, offering new possibilities for magnetic materials.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Materials with strong magnetostructural coupling exhibit complex energy landscapes with multiple accessible ground states.
- Switching between distinct magnetic-electronic properties is challenging due to limited accessibility of energy minima via equilibrium stimuli.
Purpose of the Study:
- To explore the creation of a ferromagnetic ground state above room temperature in initially paramagnetic FeRh alloys.
- To investigate the effects of nonequilibrium nanostructuring on the magnetic properties of FeRh alloys.
Main Methods:
- Dealloying process to transform bulk FeRh alloys into nanoporous structures.
- Magnetometry and Mössbauer spectroscopy to analyze magnetic ground states.
- Density functional theory calculations to validate magnetic ordering mechanisms.
Main Results:
- Nanostructuring induced a coexistence of a spin-glass and a robust ferromagnetic phase in FeRh alloys.
- Ferromagnetic phase emergence is attributed to local tetragonal distortion caused by surface stress.
- Achieved complete on/off ferromagnetic-paramagnetic switching over a wide temperature range.
Conclusions:
- Nonequilibrium nanostructuring provides a pathway to access conventionally inaccessible magnetic states.
- This method enables the creation of tunable magnetic properties in materials.
- The findings open new avenues for designing advanced magnetic materials with controllable switching capabilities.
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