Investigation of atomic structure of ω-phase crystals in Ti-Mo alloys using high-resolution electron microscopy

High-resolution electron microscope (HREM) images of ω-phase crystals in Ti-11.1at%Mo alloy single crystals formed by aging are discussed by comparing with the calculated images. The calculation was carried out using the multi-slice method at different defocus values for ω-phase crystals at three different positions in the matrix. It is found that bright spots of HREM images of ω-phase crystals appear at the positions of atoms, which are displaced in the opposite direction and make atom pairs in the model, as was proposed by de Fontaine et al. This fact was previously predicted in 1987. It is also found that bright spots of HREM images appear at the position of atoms, which are not displaced in the model. These results suggest that the proposed model is satisfactory.