Electric-transport, heat capacity, and first-principles study of non-collinear <i>β</i>-Mn type <i>Co–Zn–Mn</i> metallic magnets

Abstract

Recently, Co–Zn–Mn alloys with β-Mn type crystal structure have gained much attention due to the detection of magnetic skyrmion in a broad temperature region along with intriguing properties arising from frustrated 12d sites. This study systematically explores the experimental and theoretical transport properties of Co–Zn–Mn alloys, which are important for both fundamental understanding and practical applications. We also measured the longitudinal, ρxx(T, H = 0), Hall resistivity, ρxy, of Co10−x/2Zn10−x/2Mnx (x = 4 &amp; 6) alloys as a function of magnetic field and temperature. The total ρxy is expected to include contributions from the ordinary, anomalous, and topological Hall effects. The ρxx(T, H = 0) curve for the sample x = 6 exhibits resistivity minima at Tmin∼ 100 K, and it disappeared for the sample with x = 4. The enhanced electron–electron Coulomb interaction and weak localization are responsible for the low-temperature upturn in the ρxx(T) curve. The temperature-dependent anomalous Hall contribution, ρxyA(T), decreases with increasing temperature for both samples. The noncollinear spin configuration in Co–Zn–Mn alloys induces a topological Hall contribution, ρxyT(T), of the order ∼nΩ cm in the temperature range from 5 K to TC. The first-principles calculation reveals a complex non-collinear magnetic structure of Co–Zn–Mn alloys, which gives rise to anomalous transport behaviors.