CHARACTERISTICS OF LITHIUM LANTHANUM TITANATE THIN FILMS MADE BY ELECTRON BEAM EVAPORATION FROM NANOSTRUCTURED La0.67-xLi 3xTiO3 TARGET

Nguyen Nang Dinh (College of Technology, Vietnam National University Hanoi, 144 Xuan Thuy, Cau Giay, Hanoi)
Le Dinh Trong (Institute of Materials Science, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi)
Pham Duy Long (Institute of Materials Science, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi)

ASEAN Journal on Science and Technology for Development
Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)

Bulk nanostructured perovskites of La0.67-xLi3xTiO3 (LLTO) were prepared by using thermally ball-grinding from compounds of La2O3, Li2CO3 and TiO2. From XRD analysis, it was found that LTTO materials were crystallized with nano-size grains of an average size of 30 nm. The bulk ionic conductivity was found strongly dependent on the Li+ composition, the samples with x = 0.11 (corresponding to a La0.56Li0.33TiO3 compound) have the best ionic conductivity, which is ca. 3.2 x 10-3 S/cm at room temperature. The LLTO amorphous films were made by electron beam deposition. At room temperature the smooth films have ionic conductivity of 3.5 x 10-5  S/cm and transmittance of 80%. The optical bandgap of the films was found to be of 2.3 eV. The results have shown that the perovskite La0.56Li0.33TiO3  thin films can be used for a transparent solid electrolyte in ionic battery and in all-solid-state electrochromic devices, in particular.