Characterization of Ba0.5Sr0.5TiO3 thin films for tuneable devices

Barium strontium titanate (BST) bulk ceramic c was used as target for PLD thin film deposition. In order to avoid stoichiometry modification during the deposition, a more reactive oxidant ambient in the chamber was produced by, using a radiofrequency discharge 13.56 MHz, 150 W. Thin films of stoichiometric BST was deposited on alumina substrate with the thickness between 400 and 500 nm heated at 650 degrees C. An aditional anealing was made at 800 degrees C for 6 hours. XRD and SEM were used,for sample characterization, Capacity measurements tit 100 kHz were performed versus temperature.