TEM analysis of Gd5Si1.85Ge2.15 alloy

The material Gd5Si1.85Ge2.15 belonging to Gd5(SixGe1 − x)4 family was investigated using transmission electron microscopy. The results show that the quenched samples possess monoclinic structure at room temperature. TEM observation also revealed two distinct structure features, large amounts of twins and fine-scale faults on the (002) plane. The low temperature experiments confirmed that this material undergoes a unique, reversible, monoclinic paramagnetic to orthorhombic-I ferromagnetic transformation. It can be concluded that the transition is diffusionless and displacive in nature and is best described as a ferroelastic phase transition.