Fabrication and ionic conductivity of amorphous lithium meta-silicate thin film

Lithium meta-silicate (Li2O–SiO2, abbreviated as LSO) thin film was fabricated on SiO2 glass substrate by a pulsed laser deposition (PLD) method. By X-ray diffraction measurement, as-prepared thin film is found to have amorphous structure. Temperature and thickness dependence of the ionic conductivity was measured at the temperature range from 500 to 700 K. The amorphous thin film shows about 1 to 2 orders higher ionic conductivity than that of polycrystalline Li2SiO3. The thickness dependence of the ionic conductivity shows a local maximum at around the thickness 0.15 μm. It is considered that the thickness dependence of ionic conductivity of amorphous LSO thin film would be originated from a hetero-interface effect.