Synthesis and structure of CsLi0.5Al0.5PO4

A new phosphate CsLi0.5Al0.5PO4 with a structure related to the β-tridymite structure has been synthesized by a precipitation method. X-ray powder diffraction, electron probe microanalysis, second harmonic generation of laser radiation, and IR spectroscopy have been used for studying the compound. Differential scanning calorimetry shows that the synthesized phosphate undergoes phase transitions at T tr = 68 and 130°C. The crystal structure of CsLi0.5Al0.5PO4 was refined on the basis of X-ray powder diffraction data by the Rietveld method in space group P21/a (Z = 8) with the unit cell parameters a = 17.8323(3) Å, b = 5.4250(1) Å, c = 9.3666(2) Å, β = 89.984(8)°, V = 906.10(9) Å3.