Complete, reversible H +/Li + ion exchange reaction between rhombohedral LiMO 3 and perovskite-type HMO 3 (M=Nb, Ta)

Abstract

We demonstrate for the first time the complete, reversible H +/Li + ion exchange reaction between HMO 3 and LiMO 3 (M=Nb, Ta) using molten LiNO 3 at 320°C for 5 days. HMO 3 were prepared from LiMO 3 by ion exchange reactions using dilute HNO 3. The results reveal that both LiMO 3 prepared by normal solid state reaction between Li 2CO 3 and M 2O 5, and by ion exchanged from HMO 3 using molten LiNO 3 are isostructural. LiMO 3 prepared using HMO 3 yields nearly uniformly sized crystallites in contrast to those prepared by conventional solid state synthesis. The present method is simple and inexpensive compared to other methods of preparation of high purity LiMO 3 powders.