X-ray high temperature powder diffraction study and computer simulation of γ-LiNaCO3

Abstract

Abstract The high-temperature γ-phase of lithium sodium carbonate (γ-LiNaCO3, a = 8.311 Å, c = 3.386 Å, P[unk]) has been studied by X-ray diffraction and computer simulation methods. The results of computer simulation based on the ionic model and the temperature dependence of the superlattice reflection intensities correspond to the order-disorder type of the β – γ phase transition. The Rietveld refinement using X-ray powder data at 713 K confirms the disordered model of the structure with one of the three CO3 2− groups disordered over two sets of positions.