Structural and magneto-transport properties of Mn1+xCo1−xSn (x = 0.0-1.0) alloys

Hexagonal MnMX alloys present interesting properties like non-collinear magnetism, reentrant spin glass, novel skyrmion-domain formation, etc. In this work, we synthesized Mn1+xCo1−xSn (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) alloys using arc melting and melt spinning techniques. A pure Ni2In-type structure was obtained in alloys of x = 0.4-0.8. The lattice parameters increase systematically with an increase in the Mn content. ZFC-FC measurements show reentrant spin-glass-like and non-collinear magnetic transition, reflecting the competition of several exchange interactions. The magnetic properties also show strong dependence on the anti-site disorder. First-principles calculations are applied to explain the evolution of the magnetic state. The magnetoresistance values for all alloy ribbons are negative and linearly changed, dominated by the spin-dependent scattering. Both magnetoresistance and anomalous Hall effect show hysteresis at low temperatures, consistent with the magnetization measurements.