Magnetic properties of hexagonal and cubic Fe3Ge

The hexagonal and cubic phases of the intermetallic compound Fe 3 Ge have been investigated with the Mossbauer effect technique and magnetization measurements. In both phases the material is ferromagnetic with T c =640K and mu Fe =2.0 mu B (hexagonal), and T c =740K and mu Fe =2.2 mu B (cubic). In the hexagonal phase a spin-flip is observed at 380K. This transition appears to be of second order. In the cubic phase the preferred spin direction is (100). In this phase the anisotropic part of the hyperfine field at the 57 Fe nucleus is large (+18 kOe). The origin of this anisotropy is discussed.