Synthesis of a New Ferromagnetic Intermetallic Compound, Mn₃Ge, with the L1₂-Type Structure

Abstract

A new intermetallic compound, Mn₃Ge, has been synthesized from the elemental components under high-pressure condition. The Rietveld analysis of the powder X-ray diffraction data revealed that the compound crystallizes into the cubic L1₂-type (Cu₃Au-type) structure with the lattice parameter of a=0.38019 (3)nm. The result, as well as our former results on high-pressure synthesis of manganese germanides, suggests a remarkable change in binary Mn-Ge phase diagram under high-pressure condition. Mn₃Ge exhibits metallic conduction and ferromagnetic behavior with a Curie temperature of 400K. The saturation magnetic moment is 0.87μB/Mn, indicating a possible itinerant electron ferromagnetism. The magnetic properties of Mn₃Ge are discussed with isomorphous compounds and structurally related perovskite-type Mn₃MC (M=A1, Ga, In, Zn, Sn) compounds.