Interpretation of High Resolution Transmission Electron Microscope Images of Short Range Ordered Ni₄Mo

Abstract

High resolution transmission electron microscope (HRTEM) image contrast of short-range order (SRO) in Ni₄Mo alloys has been investigated by means of multi-slice simulations. The HRTEM image contrast of SRO in Ni₄Mo coincides with a projection contrast of an SRO structure which involves D1_a, D0₂₂ and Pt₂Mo-type subunit cells in a disordered matrix. Multi-slice simulations revealed that the SRO structure exhibit a projection contrast in the HRTEM image when the fundamental fcc lattice reflections contribute sufficiently to HRTEM imaging. The results indicate that the image of SRO in Ni₄Mo can be interpreted in terms of projected potential of atomic columns under an appropriate imaging condition.