Correlation between dielectric properties and strain in Pb0.5Sr0.5TiO3 thin films prepared by using the sol-gel method

Abstract

Pb0.5Sr0.5TiO3 (PST) thin films were fabricated by the alkoxide-based sol-gel process using spin-coating method on Pt/Ti/SiO2/Si substrate. The PST films annealed from 500 degreesC to 650 degreesC for 1 h show a perovskite phase and dense microstructure with a smooth surface. The grain size and dielectric constant of PST films increase with the increase in annealing temperature, which reduces the SiO2 equivalent thickness of the PST film. The crystallinity or internal strain in the PST thin films analyzed from the diffraction-peak widths correlates well with the decrease in the dielectric losses. The dielectric constants and dielectric loss (%) of the PST films annealed at 650 degreesC (t(eq) = 0. 89 nm) were 549 and 0.21%, respectively. (C) 2004 Elsevier B.V. All rights reserved.