We report on the epitaxial growth of LiNbO3 (112̄0) films on sapphire (112̄0) substrates using pulsed laser deposition. We have used a Li-enriched target of Li2NbO3 to compensate for the loss of Li at high deposition temperatures of 600-800 °C. X-ray θ-2θ scans reveal that the crystal orientation of our LiNbO3 films is very sensitive to the deposition temperature and oxygen pressure. To obtain a single (112̄0) orientation, we need to use a deposition temperature of 800 °C and an oxygen pressure of 10-5 Torr. Otherwise, an extra (0001) orientation of LiNbO3 always occurs. From a rocking curve of the (112̄0) peak, we have measured a full width at half maximum of 0.3°, implying that our LiNbO3 (112̄0) film is highly oriented. The measured dielectric constants of the LiNbO3 (0001) and (112̄0) films at 1 MHz are 80 and 70, respectively.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Control and Systems Engineering
- Ceramics and Composites
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry