Preparation of Li_2TiO_3 by hydrothermal synthesis and its structure evolution under high energy Ar~+ irradiation

摘要

Ultrafine lithium titanate (Li_2TiO_3) powder was synthesized by hydrothermal method. The phase formation and transition condition among α,β, and γ-Li_2TiO_3 were discussed. XRD and ICP-AES showed the single a-phase was formed at 180 C with 2 h hydrothermal reaction, and it transited into B-phase at 400°C. SEM observation and EDS analysis confirmed the dissolution of TiO_2 and the formation of α-Li_2TiO_3 proceeded simultaneously with preferable growth direction of (-133) lattice. During the phase transition, the powder maintained the small crystallite, which facilitated the fabrication of Li_2TiO_3 bulk with small grain size. After the Ar~+ irradiation, the surface region to the depth of 3 μm of Li_2TiO_3 ceramic was affected, where the decrease of crystallization and disturbance of short-range order were confirmed by GIXRD and Raman spectroscopy. In spite of the structure change at the surface area, the ceramic bulk maintained the same.