Preparation, structural characterization and conductivity of LiZr2(PO4)3

Amorphous LiZr2(PO4)3 has been prepared at room temperature starting from aqueous solutions of ZrOCl2, H3PO4, and LiOH and then crystallized by heating at temperatures between 600 and 900°C. The material obtained at 900°C has been characterized by X-ray powder diffractometry, DSC analysis, and ac conductivity. It is monoclinic from 20 up to about 300°C and orthorhombic at higher temperatures. A change in the activation energy for conduction (from 0.79 to 0.43 eV) and a weak endothermic effect (0.9–1.7 cal/g) are associated with the phase transition. The ac conductivity of sintered pellets is, on average, 7×10−4 S cm−1 at 300°C.