Phase transitions in LiKSO4 between 1.5 K and 850 K: an infrared spectroscopic study

作者：Zhang M^*; Salje EKH; Putnis A

来源：Journal of Physics: Condensed Matter , 1998, 10(50): 11811-11827.

DOI：10.1088/0953-8984/10/50/019

A systematic infrared spectroscopic investigation of the sequence of phase transitions in LiKSiO4 at temperatures between 1.5 K and 850 K in the region of 50-1500 cm(-1) is reported. IR powder spectra show phase transitions near 35 K, 60 K, 140 K, 190 K, 240 K and 708 K on heating. The transitions are characterized either by the appearance of new IR bands, IR band splitting or a change in the temperature dependence of spectral profiles. The numbers of internal bands show that the phases in the temperature regions of 140-190 K and 190-240 K consist of a monoclinic (space group Cc) and a trigonal (space group P31c) structure, respectively. The observation of two nu(2) IR modes between 140 and 190 K rules out the orthorhombic structure of C-2 upsilon(12) (Cmc2(1)). Symmetry changes occur at the phase transitions at 135 K and 60 K.

• 出版日期1998-12-21