The magnetic properties of the manganese-gallium-aluminum-germanium system

The properties of solid solutions of composition MnGa1-xAlxGe formed from ferromagnetic MnGaGe (Tc = 185°C) and MnAlGe (Tc = 245°C) have been examined. In the range, 0 < x < 0.1, the Curie temperature and saturation magnetization are not a monotonic function of x as might be expected for a solid solution of two ferromagnets. Instead, for x = 0.025, the Curie temperature is actually ∼77°C lower than that of MnGaGe. Despite the similarity in the structure and lattice constants of MnGaGe and MnAlGe, aluminum rich compositions, e.g., x = 0.95 show no solid solution. Attempts to prepare other ferromagnetic ternary Mn (IIIA) (IVA) compounds have not been successful. © 1973.