Magnetic and Structural Properties of Metamagnetic MnCo_0.92Fe_0.08Ge Compound

抄録

The magnetic and structural properties of ferromagnetic MnCo_0.92Fe_0.08Ge were investigated by magnetization and X-ray powder diffraction measurements in magnetic fields up to 5 T. The compound showed first-order transition between the paramagnetic and ferromagnetic state with a thermal hysteresis of approximately 24 K, which was accompanied by the martensitic transformation from the hexagonal Ni₂In-type structure to the orthorhombic TiNiSi-type structure in the vicinity of 275 K. The cell volume expanded by 4.1% during the martensitic transformation. The magnetic moment of MnCo_0.92Fe_0.08Ge was estimated to be 111 Am² kg⁻¹ (3.7 μ_B/f.u.) at 10 K. The compound showed both metamagnetic transition and magnetic field-induced martensitic transformation.