X-ray and electron diffraction study on the partial disordering of the Γ-phase in the Fe-Zn system

The temperature dependence of the degree of order has been studied by X-ray and electron diffraction on polycrystalline specimens on single phase of the Γ-Fe3Zn10 phase in the Fe-Zn system. The X-ray intensity of superlattice peaks started to decrease above 500°C. The intensity of the superlattice peaks recovered on the subsequent cooling; in other words the intensity change was reversible. The electron diffraction patterns obtained on quenched specimens also showed that the superlattice structure of this phase was partially disordered at high temperatures. It is suggested that the improved plasticity of the Γ-phase at high temperatures is to be attributed to the partial disordering.