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 0.87 μB/Mn, indicating a possible itinerant electron ferromagnetism. The magnetic properties of Mn3Ge are discussed with isomorphous compounds and structurally related perovskite-type Mn3MC (M = Al, Ga, In, Zn, Sn) compounds.