Temperature dependence of optical and structural properties of ferroelectric B3.15Nd0.85Ti3O12 thin film derived by sol–gel process

• DOI: 10.1007/s10971-011-2619-0
• Publication Date: 2011-11-08T10:52:48Z
• Authors: Yongyuan Zang; Dan Xie; Yu Chen; Mohan Li; Chen Chen; Tianling Ren; David Plant
• Keywords: Spin Coating; Ellipsometry

We report the annealing temperature dependence of optical properties in ferroelectric B3.15Nd0.85Ti3O12 (BNdT) thin film for the first time. BNdT thin films are prepared by a sol–gel/spin coating method. Structural properties of BNdT thin films upon different thickness and annealing temperatures are characterized using the X-ray diffraction, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The BNdT thin film annealed at 650 °C exhibits a well defined perovskite crystalline structure with high c-axis orientation, which leads to a saturated polarization–electric field (PE) hysteresis with a remanent polarization of 2P r = 39.6 μC/cm2 and coercive field of 85 kV/cm at 5 V. Little fatigue degradation ( 80% is observed for wavelengths from 250 to 2,000 nm. Fundamental optical parameters of BNdT material such as refractive index n, extinction coefficient k, and band gap energy E g are extracted from an ellipsometry measurement. Microstructure and annealing temperature dependence of T(λ), n, k, and E g variation are also investigated and explained in detail.