Crystallographic and magnetic properties of Mn 2 GeTe 4 and Fe 2 GeTe 4 compounds
X ray powder diffraction measurements, at room temperature, and magnetic susceptibility kh measurements, in the temperature range from 2 to 300 K, were made on polycrystalline samples of Mn 2GeTe4 and Fe2GeTe4 compounds, which would be useful for spintronic device production. Magnetization measurements at various temperatures were carried out on these compounds. From the analysis of the x ray diffraction lines, it was found that both Mn 2GeTe4 and Fe2GeTe4 have an orthorhombic olivine structure type (SG: Pnma No. 62, z=4) It was found that Mn2GeTe4 has a Neel temperature of 30 K and shows mainly antiferromagnetic behaviour with a weak superimposed ferromagnetic component which is attributed to spin canting. The resulting 1/ kh versus T curve for Fe 2GeTe4 was found to have a form which is typical of a ferromagnetic material with a Curie temperature T C of 149.9 K.