Raman scattering and phase transitions in fluorides with elpasolite structure

Vtyurin, A; Krylov, A; Voronov, V; Krylova, S FERROELECTRICS, 512 (1):58-64; 10.1080/00150193.2017.1349863 2 2017

Raman scattering spectra of Rb2KHoF6 and Rb2KDyF6 crystals have been studied in temperature range from 20 K to 399 K and from 7 K to 500 K respectively. Raman spectra of Rb2KHoF6 crystal are distorted due to the fluorescence process. Parameters of Raman lines have been quantitatively analyzed. The investigation points to the considerable role of CX6 groups in the temperature phase transition in Rb2KHoF6 and Rb2KDyF6 crystals. The anomalies of spectra changes with temperature testify the first order phase transitions in these crystals.