论文部分内容阅读
Optical vibrations of the lattice and the electron-phonon interaction in polar teary mixed crystals are studied in the framework of the continuum model of Bo and Huang and the random-element-isodisplacement model. A normal-coordinate system to describe the optical vibration in teary mixed crystals is correctly adopted to derive a new Frohlich-like Hamiltonian for the electron-phonon interaction including the unit-cell volume variation influence.The numerical results for the phonon modes, the electron-phonon coupling constants and the polaronic energies for several typical materials are obtained. It is verified that the nonlinearity of the electron-phonon coupling effects with the composition is essential and the unit-cell volume effects cannot be neglected for most teary mixed crystals.