Optical and Electrical Properties of Nanocrystalline La₀.₄Sr₀.₆TiO₃ Thin Films
Optical and electrical properties of nanocrystalline La0.4Sr0.6TiO3 thin films
The effects of microstructure on the optical properties of La0.4Sr0.6TiO3 thin films were investigated. Dense films with a thickness of about 200 nm were produced on monocrystalline sapphire substrates using a polymeric precursor spin coating technique. The films were annealed over the temperature range 500-800 C. X-ray data showed the formation of a single cubic perovskite-type structure similar to undoped SrTiO3 for annealing temperatures > 500 C. The grain size was varied from 16 to 30 nm by annealing at temperatures up to about 800 C. Electrical and optical measurements showed a correlation with the microstructure of the films, and the electrical conductivity and optical spectra varied with changes in grain size. From these data, the absorption coefficients were calculated and the band gap energy determined. It was shown that the band gap energy increased as the grain size decreased, which can be explained by the quantum confinement effect.
T. Suzuki et al., "Optical and Electrical Properties of Nanocrystalline La₀.₄Sr₀.₆TiO₃ Thin Films," Ceramic Transactions, American Ceramic Society, Apr 2004.
Materials Science and Engineering
Keywords and Phrases
Absorption Coefficient; Annealing; Correlation Analysis; Electrical Conductivity; Electrical Resistivity; Energy Gap; Grain Size; Microstructure; Nanocrystals; Optical Measurement; Optical Properties; Polymeric Precursors; Quantum Confinement; Spin Coating; Thin Films
Article - Conference proceedings
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