X-Ray Study of Ferrielastic Phase Transition in CsLiCrO4Crystal

The orthorhombic to monoclinic phase transition in CsLiCrO 4 crystal has been studied with X-ray diffraction to clarify the mechanism of the phase transition. Temperature dependence of lattice constants a , b , c , γ and integrated intensity of Bragg reflections ( h 0 l ) has been measured. The experimental results are analyzed on the basis of two-sublattice ferrielastic model. It has been found that CsLiCrO 4 crystal has two kinds of sublattice order parameters with a fast-ordering component q 1 and a slow-ordering component q 2 . The former is associated with ordering of CrO 4 sublattice, while the latter with ordering of Cs sublattice. CsLiCrO 4 crystal is the first ferrielastics which has been proved from microscopic point of view to consist of two kinds of sublattice strains with opposite signs and different magnitudes.