Inverted magnetic response in severe plastically deformed nanostructured high-entropy alloy

TY - JOUR

T1 - Inverted magnetic response in severe plastically deformed nanostructured high-entropy alloy

AU - Paul, Amitesh

AU - Liu, Xiaojing

AU - Kawasaki, Megumi

AU - Liss, Klaus-Dieter

N1 - Publisher Copyright: © 2023 Author(s).

PY - 2023/1/30

Y1 - 2023/1/30

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85147332377&partnerID=8YFLogxK

U2 - 10.1063/5.0138040

DO - 10.1063/5.0138040

M3 - 文章

SN - 0003-6951

VL - 122

JO - Applied Physics Letters

JF - Applied Physics Letters

IS - 5

M1 - 052402

ER -