Lithium-ion conducting La_(2/3-x)Li_(3x)TiO_3 solid electrolyte thin films with stepped and terraced surfaces

摘要

La_(2/3-x)Li_(3x)TiO_3 (LLT, x = 0.1 and 0.167) thin films were grown on (001)-oriented SrTiO_3 (STO) substrates by pulsed laser deposition. The resultant LLT films were heteroepitaxially grown with atomically flat surfaces. Although the films considered to be single crystalline, they were composed of 90°-rotated multi domains (~5 nm in size) with epitaxial relationships of (100) [001] LLT ‖(001) [100] STO and (100) [010] LLT ‖ (001) [100] STO. The bulk conductivity of the LLT (x= 0.1) films was 2.5 × 10~(-2)S cm~(-1) at 190 ℃, comparable to that of a bulk single crystalline LLT. Single crystalline LLT thin films with atomically flat surfaces should help clarify interfacial lithium-ion conductivity.