Characteristics of yttrium substituted sodium bismuth titanate thin films

Sodium bismuth titanate (NBT) thin films substituted with yttrium for Na site were prepared by a modified sol-gel processing and their dielectric properties were investigated. The stability of perovskite structure was highly affected by the amount of Y substitution and the annealing temperatures. Y substituted NBT thin films post-annealed at 750 degrees C exhibited uniform microstructures associated with grain growth inhibition. Relative permittivity and remnant polarization were maximized at 5 mol% Y substitution and loss tangents for all the prepared films were relatively stable with less than 0.03. It was also found that the substitution of yttrium led to the enhancement of diffuse phase transition for the NBT thin films. (C) 2010 Elsevier B.V. All rights reserved.