Temperature study of (SrAl0.5Ta0.5O3)1−x−y:(LaAlO3)x:(CaAl0.5Ta0.5O3)y mixed perovskite crystals by Raman spectroscopy

Temperature Raman scattering study were carried out for three component SAT1−x−y:LAx:CATy crystals with two different compositions. The low and high temperature investigations have been performed for SAT0.5:LA0.125:CAT0.375 and SAT0.24:LA0.06:CAT0.7 crystals in the spectral range 80-1000 cm−1. The Raman spectra obtained at room temperature for both crystals are different in the range of external F2g(1) and internal bending F2g(2) vibrational modes. During temperature study of SAT0.5:LA0.125:CAT0.375 and SAT0.24:LA0.06:CAT0.7 crystals, double and triple structure of F2g(1) mode has been observed in the whole temperature range. Double and triple structure of internal F2g(2) mode was observed for SAT0.5:LA0.125:CAT0.375 and SAT0.24:LA0.06:CAT0.7 crystals, respectively. However, one mode character of F2g(2) mode was stated for SAT0.5:LA0.125:CAT0.375 crystal at 630 K. A monotonous temperature changes in bands position for investigated crystals confirm both, stable character of static distortions and luck of any structural phase transition in these crystals in temperature range studied.