Analysis of the peak position and linewidth as a function of temperature for the phase transitions in LiKSO4

Abstract

Analysis of the peak position and the linewidths of various infrared modes is performed at high (300–850 K) and low (1.5–300 K) temperatures using the experimental data from the literature for LiKSO4 which exhibits a sequence of phase transitions. The temperature dependences of the frequency and the linewidth which are derived from the anharmonic self-energy are fitted to the observed peak positions and the linewidths of the S–O stretching modes (internal [Formula: see text] modes at 1135 cm[Formula: see text] and at 1180 cm[Formula: see text]), peak position of the S–O bending [Formula: see text] (internal) modes, the peak position and the linewidth of the Li mode at 429 cm[Formula: see text] (external mode), and of the infrared band at 363 cm[Formula: see text] for LiKSO4. Our calculated peak positions and the linewidths, which are in good agreement with the observed data show that the anharmonic self-energy model describes adequately the observed behavior of the successive phase transitions in LiKSO4.