Phase diagram of pseudomorphic binary semiconductor compound cry stal

摘要

Elastic strain energy contributiojn to the molar Gibbs free energy of a binary compound semiconductor crystal coherently coupled to the isomorphous substrate with large lattice mismathc results in drastic modification of the familiar phase diagram. Sizable depression of the melting point and large shifts in eutection temperature and composition are predicted Due to elastic anisotoropy of cubic crystals these effects are explicitly orientation-denendent. The general model is illustrate by calculation of T-x and P-T projections of a three-phase equilibrium line of pseudomorphic InAs substrate with different singular orientations. Extension of the model to the case of homoepitaxy is suggested by phenomenologically taking several atomic layers of a reconstructed surface as a nonhydrostatically stressed crystal.