Barium strontium titanate (BST) bulk ceramic with composition Ba0.5Sr0.5TiO3 was produced by solid-state reaction and was used as target for PLD thin film deposition. A Nd-YAG laser, working at 5-10 Hz and different wavelengths has been used. Thin films of stoichiometric BST were deposited on alumina substrate with the thickness between 400 and 500 nm. An aditional annealing was carried out at 800 degrees C for 6 h. XRD and SEM were used for sample characterization. Capacity measurements were performed versus temperature at 100 kHz in a large temperature range. A diffuse ferroelectric-paraelectric phase transition with T-C = -72 degrees C for the BST thin film was determined. A 5% tunability was measured in the transition region. (c) 2007 Elsevier B.V. All rights reserved.