Mictomagnetism and suppressed thermal conduction of the prototype high-entropy alloy CrMnFeCoNi

Abstract

• CrMnFeCoNi is found to be mictomagnetic. • There is weak lattice anharmonicity in CrMnFeCoNi. • The thermal conductivity is reduced down to about 10% of nickel due to disorder scattering. • Lattice of CrMnFeCoNi is remarkably softened compared to nickel. High-entropy alloys are characteristic of extensive atomic occupational disorder on high-symmetric lattices, differing from traditional alloys. Here, we investigate the magnetic and thermal transport properties of the prototype face-centered-cubic high-entropy alloy CrMnFeCoNi by combining physical properties measurements and neutron scattering. Direct-current and alternating-current magnetizations measurements indicate a mictomagnetic behavior with coexisting antiferromagnetic and ferromagnetic interactions below room temperature and three anomalies are found at about 80, 40, and 20 K, which are related to the paramagnetic to antiferromagnetic transition, the antiferromagnetic to ferromagnetic transition, and the spin freezing, respectively. The electrical and thermal conductivities are significantly reduced compared to Ni, and the temperature dependence of lattice thermal conductivity exhibits a glass-like plateau. Inelastic neutron scattering measurements suggest weak anharmonicity so that the thermal transport is expected to be dominated by the defect scattering.