Preparation of solid electrolyte Ta-substituted Li₇La₃Zr₂O₁₂ epitaxial thin film using LiOH-flux liquid phase epitaxy

Abstract

Solid electrolyte Ta-substituted Li₇La₃Zr₂O₁₂ (LLZTO) epitaxial thin films were grown using LiOH-flux liquid phase epitaxy at 600 °C under the flow of N₂ and H₂O vapor mixture. Prior to the liquid phase epitaxy, amorphous La–Zr–Ta–O thin films were deposited on garnet-type Ga₃Gd₅O₁₂ (GGG) substrates by dynamic aurora pulsed laser deposition for the thickness limitation and uniform film formation. Obtained thin films after liquid phase epitaxy, include Li content by X-ray photoemission spectroscopy. The epitaxial growth of LLZTO thin films on GGG(001), (110) and (111) substrates were confirmed by pole figures. The thin films had relatively low out-of-plane orientation degree despite liquid phase method. The surface observation reveals that the thin film surfaces consist of radially spreading regions with about 5–20 µm, which implies that the growth condition in this study was at higher supersaturation degree.