Inverted magnetic response in severe plastically deformed nanostructured high-entropy alloy
| Autor: | Amitesh Paul, Xiaojing Liu, Megumi Kawasaki, Klaus-Dieter Liss |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Applied Physics Letters. 122:052402 |
| ISSN: | 1077-3118 0003-6951 |
| Popis: | We present unconventional magnetization in a high-pressure torsion (HPT) CoCrFeNi nanostructured high-entropy alloy: (i) the temperature dependent magnetization protocol and DC susceptibility suggest effects of spin-clustering. Moreover, HPT-processing of the alloy produces a heterogeneous and metastable nanostructure, changing its supermagnetic character: turning superparamagnetic to superspin glass dynamics, (ii) the material shows an inverted magnetic hysteresis loop, an inversion of the central part of the loop where the remanent magnetization points in a direction opposite to the applied field. The exquisite tunability of this inverted magnetism as a function of field and temperature and its reproducibility in a quasi-equilibrium setting make this spin-clustering phenomenon unique. We account for this phenomenon in terms of a non-equilibrium population of oppositely polarized domains of an ordered ferromagnetic state, enabled through the nanostructured, highly distorted, and locally disordered crystalline medium. |
| Databáze: | OpenAIRE |
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