Effect of Ga substitution for Ge on magnetic and crystal properties of the GdMnGe1−x Gax intermetallics

The magnetic properties of the GdMnGe and the GdMnGe0.5Ga0.5 intermetallic compounds have been investigated by magnetization and susceptibility measurements in a broad temperature range for the purpose to explain the influence of the substitution of germanium by gallium on the magnetic and crystalline properties of the new ternary GdMnGe0.5Ga0.5 compound. The X-ray phase analysis and the metallographic analysis have shown: the orthorhombic TiNiSi-type structure and the hexagonal ZrNiAl-type structure for GdMnGe and for GdMnGe0.5Ga0.5, respectively. It was shown, that replacing Ga for Ge significantly influences the magnetic ordering. The GdMnGe displays a complex antiferromagnetic structures with phase transition temperature T1=100 K and the Néel temperature equal to 350 K, as in turn the GdMnGe0.5Ga0.5 exhibits ferrimagnetic type behavior with TN=170 K.