Magnetocrystalline anisotropy of Fe3Ge single crystal: Effect of pressure and Mn substitution for Fe.

The temperature dependence of the magnetocrystalline anisotropy and the effects of pressure on the intrinsic magnetic properties of the hexagonal DO₁₉ phase of Fe₃Ge single crystals have been studied. The easy-magnetization direction is in the basal plane at low temperatures and a spin reorientation transition from plane to axis occurs at 377 K, with increasing temperature. The thermal dependence of the magnetic anisotropy of Fe₃Ge has been determined and described in the frame of the Carr model for localized moments. The partial substitution of Fe by Mn, besides reducing both the saturation magnetization and Curie temperature, extends the axial region widely. Pressure has little influence on the magnetic moment but it markedly affects the crystalline anisotropy. The planar character of the anisotropy is indeed reduced in both pure and substituted compounds. The application of high pressure, the partial substitution of Fe by Mn and the increase of temperature have similar effects on the magnetocrystalline anisotropy of Fe₃Ge—all induce a reduction of its planar character, favoring a plane to axis spin reorientation transition. [ABSTRACT FROM AUTHOR]