Effects of the sol concentration on the texture of Pb0.3Sr0.7TiO3 thin films derived by sol–gel method

Pb 0.3 Sr 0.7 TiO 3 (PST) thin films were deposited on Pt coated Si (100) substrates by sol–gel techniques using a series of different sol concentrations (0.15, 0.20, 0.25, 0.30, and 0.40 M). Both structural and dielectric characteristics of PST films as a function of the sol concentration were investigated. PST thin films reveal typical crystalline structure with columnar texture when the sol concentration is lower than 0.30 M. With the concentration increasing up to 0.30 M, the columnar-grained structures can not be obtained. Among all the PST thin films, the thin film derived with 0.25 M sol has better dielectric characteristics. The dielectric constant, dielectric loss, tunability and FOM are 329, 0.011, 58.0% and 52.8, respectively.