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

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, m_eff = 2.71 μ_B/f.u., were observed. A negative value of the paramagnetic Curie temperature, θ_C = −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 m_cl = 0.275 μ_B/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, dT_ord/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.