Effects of the sol-concentration on the structural and dielectric properties of Pb0.3Sr0.7TiO3 thin films derived by the sol-gel method

Pb_0.3Sr_0.7TiO₃(PST) thin films were deposited on Pt coated Si(100) substrates by sol-gel techniques using different sol-concentrations. The structural and dielectric characteristics of lead strontium titanate (PST) thin films as a function of the sol-concentration were investigated. PST thin films reveal a columnar texture through the thickness when the sol-concentration is lower than 0.30 M. PST thin films derived from 0.35 M sol show better dielectric characteristics with the dielectric constant, dielectric loss, tunability, and field of motion (FOM) (tun- ability/dissipation) of 200, 0.01, 47% and 47, respectively. The temperature dependence of the dielectric constant, dielectric loss and tunability of PST thin films were investigated in the temperature range of -140 to 120degC exhibiting a dielectric peak of about -45degC.