Preceding Phenomena of Martensitic Phase Transition in AgCd

Electron diffraction study on the preceding states of martensitic phase transition in AgCd shows that small β 2 phase domains are formed as embryos of the martensites. Their formation process depends strongly on the surrounding stress field. Each domain contains various degrees of the shear, which are introduced in order to release the stress field. Anomalous diffraction phenomena of the β 2 phase regions are observed and they are explained by a model of the sheared β 2 lattice.