Temperature dependences of phonon and mobile-ion spectra in superionic conductor CuBr Original Research Article

The temperature dependence of far-infrared reflectivity spectra in sintered CuBr has been measured from 18 to 570 K. Phonon and mobile-ion parameters are evaluated by the fitting procedure with the factored form of the dispersion relation. A strong fourth order anharmonicity is assigned. Estimated values of optical dielectric constant and optical ionic mobility μop decrease with increasing temperature within a limited temperature region. For μop value, the effects of mobile ion scattering by optical phonons and of the expansion of interionic distance are discussed with respect to the phonon damping constant and the ionic character of the interionic force.