Optical properties of sodium bismuth titanate thin films

We have investigated the optical and microwave dielectric properties of lead-free perovskite ferroelectric Na0.5Bi0.5TiO3 (NBT) thin films deposited on fused silica substrate using pulsed laser deposition at different substrate temperatures. The refractive index over a wide range of wavelength fits well with the single effective oscillator model. The XRD pattern shows polycrystalline nature with very small crystallite size. Dielectric properties of materials in microwave frequency range are measured by a resonant method. High transmittance shown by the NBT thin films along with their superior optical characteristics makes NBT a promising candidate for various photonic and microwave device applications.