Effect of Deformation on the Magnetic Properties of CrMnFeCoNi and CrMnFeCoNi-CN High-Entropy Alloys

Abstract

The magnetic behavior of two high-entropy alloys, CrMnFeCoNi and CrMnFeCoNi-CN, was investigated under varying degrees of deformation through uniaxial tensile tests. Microstructural, morphological, and crystalline structural analyses using XRD and SEM revealed a uniform and stable austenitic structure in all samples, with no presence of α’-martensite or ε-martensite phases. The main deformation mechanisms identified were twinning and slip dislocation for the CrMnFeCoNi-CN alloy, and slip dislocation for the CrMnFeCoNi alloy at room temperature. The alloys exhibited low magnetic moments attributed to magnetically frustrated configurations. At temperatures below 70 K, distinct magnetic states were observed ranging from paramagnetic to ferrimagnetic and spin-glass-like behavior. Antiferromagnetic interactions were confirmed by a negative paramagnetic Curie temperature for both alloys. The magnetization of the CrMnFeCoNi alloy increased with deformation, reflected in effective magnetic moments varying from 1.81 (0 pct) to 2.60 (20 pct) μB, while for the CrMnFeCoNi-CN alloy remained stable around 2.39 to 2.48 μB. The magnetization of the CrMnFeCoNi-CN alloy was found to be higher than that of the CrMnFeCoNi alloy, suggesting that the presence of C and N as alloying elements can enhance magnetization to some extent.