Soft Mode Spectroscopy in Potassium Dihydrogen Phosphate

Abstract

Abstract The infrared reflectivity spectra polarized along the c ‐axis of potassium dihydrogen phosphate are studied for both, the ferro‐ and paraelectric phase, over a wide temperature range: 10 to 420 K. The reflectivity spectra are fitted to the factorized form of the dielectric function. The temperature dependence of the optical mode parameters: frequencies, damping, and oscillator strengths are reported for both the phases. The analysis shows that besides the soft mode, a relaxational process of the very low‐frequency region plays an important role near the phase‐transition temperature.