Temperature dependence of vibrational properties in a sintered SrZrO3

Infrared reflectivity spectra of a sintered SrZrO3 have been recorded from 20 to 2000 cm−1 between 37 and 953 K. Eight intense bands are observed at 293 K and, at low temperature, each band splits into three bands, characteristic of an orthorhombic crystal structure. For phonon bands in the high frequency region, the transverse–longitudinal (TO–LO) splitting shows an almost constant value but, for the bands in low frequency region, it shows a decrease reaching to zero near 650 K. Comparing this value with that observed on cubic perovskite-type oxides, we suggest the contribution of large phonon damping and a high polarization of the OH bond on proton conduction.