Effect of high pressure on magnetic properties of CrMnFeCoNi high entropy alloy

článek v časopise ve Web of Science, Jimp

en

The temperature and magnetic field dependences of magnetization of the Cantor CrMnFeCoNi alloy were studied at ambient and high (up to 1 GPa) external pressure. The low-temperature spin-glass-like behavior and the paramagnetic behavior at temperatures above 100 K with effective paramagnetic moment of the alloy, meff=2.71 μB/f.u., were observed. A negative value of the paramagnetic Curie temperature, θC=−210 K, was found that confirms a presence of strong antiferromagnetic interactions of moments in the alloy. A model of the magnetic clusters with the effective moment of mcl=0.275 μB/f.u. provides a possibility to describe qualitatively the pronounced difference between the pressure-induced decrease of magnetization of the ZFC and the FC alloys, dlnM/dP(5 K)=−15.5*10−3 GPa−1 and −39.2*10−3 GPa−1, respectively. The former value is in an excellent agreement with the value of −16*10−3 GPa−1 obtained from our quantum–mechanical calculations. The negative pressure shift of the ordering temperature of the alloy, dTord/dP=−9 K/GPa, and the pressure-induced decrease of magnetization of the alloy in paramagnetic state, dlnM/dP(90 K)=−70*10−3 GPa−1, indicate a possible itinerant character of magnetism of the alloy. The results of theoretical calculations of the total moment of the CrMnFeCoNi fcc-alloy are discussed.

The temperature and magnetic field dependences of magnetization of the Cantor CrMnFeCoNi alloy were studied at ambient and high (up to 1 GPa) external pressure. The low-temperature spin-glass-like behavior and the paramagnetic behavior at temperatures above 100 K with effective paramagnetic moment of the alloy, meff=2.71 μB/f.u., were observed. A negative value of the paramagnetic Curie temperature, θC=−210 K, was found that confirms a presence of strong antiferromagnetic interactions of moments in the alloy. A model of the magnetic clusters with the effective moment of mcl=0.275 μB/f.u. provides a possibility to describe qualitatively the pronounced difference between the pressure-induced decrease of magnetization of the ZFC and the FC alloys, dlnM/dP(5 K)=−15.5*10−3 GPa−1 and −39.2*10−3 GPa−1, respectively. The former value is in an excellent agreement with the value of −16*10−3 GPa−1 obtained from our quantum–mechanical calculations. The negative pressure shift of the ordering temperature of the alloy, dTord/dP=−9 K/GPa, and the pressure-induced decrease of magnetization of the alloy in paramagnetic state, dlnM/dP(90 K)=−70*10−3 GPa−1, indicate a possible itinerant character of magnetism of the alloy. The results of theoretical calculations of the total moment of the CrMnFeCoNi fcc-alloy are discussed.

High entropy alloy; CrMnFeCoNi; Magnetization; High pressure

01.10.2019

1873-4766

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