Interfacial observations of Ni/Ni3Si and Ni/Ni3Ga diffusion couples

Microstructural observations and selected-area electron diffraction analyses are conducted around the diffusion-couple interfaces of Ni/Ni Si and Ni/Ni Ga. 3 3 The Ni-rich solid solution phase (eta phase) grows towards the Ni Si- or Ni Ga3 3 based intermetallic phase (eta phase) during diffusion annealing and there exists the same crystallographic orientation relationship between the eta and eta phases. It is demonstrated that this growth process and structural faeatures are characteristic of the diffusion couples between pure Ni and Ni-based intermetallics with the L1-type crystal structure. It is shown that the focused2 ion-beam cutting technique is a useful tool for preparing thin specimens for transmission electron microscopy.