Ferroelectric ${\mathrm{Sr}}_{0.60}$${\mathrm{Ba}}_{0.40}$${\mathrm{Nb}}_2$${\mathrm{O}}_6$ thin films by the sol-gel process: Electrical and optical properties

Transparent ferroelectric strontium barium niobate (SBN) thin films were made on fused silica, silicon, and GaAs substrates by the sol-gel process. The microstructure of these thin films was studied. Preferentially oriented SBN thin films on fused silica substrates can be obtained by applying a dc electric field during heat treatment. A heterojunction effect was further confirmed by the demonstration of photocurrent. The optical, pyroelectric, ferroelectric, and electro-optic properties of the SBN films were measured. An optical refractive index of 2.31 and effective linear electric-optic coefficient of 30×${10}^{\mathrm{-}12}$ m/V were obtained on the film.