Magnetic and Structural Properties of MnCoGe with Minimal Fe and Sn Substitution

抄録

The magnetic and structural properties of MnCo_0.92Fe_0.08Ge_1−xSn_x (x = 0.02, 0.05, and 0.1) were investigated. A first-order magnetic transition was observed, which was accompanied by the martensitic transformation from a hexagonal Ni₂In-type to an orthorhombic TiNiSi-type structure in the vicinity of 320 K for x = 0.02 and 170 K for x = 0.05 with thermal hysteresis of approximately 20 K. The magnetization of MnCo_0.92Fe_0.08Ge_0.95Sn_0.05 was estimated to be 102 Am² kg⁻¹ in 5 T at 10 K. High field magnetization curves up to 55 T for MnCo_0.92Fe_0.08Ge_0.95Sn_0.05 indicated the field-induced martensitic transformation. Mössbauer spectroscopy experiments revealed that Fe atoms occupied 79%–85% in the Co-site and 21%–15% in the Mn-site.