Characterization of Ni-doped BST thin films on LSCO buffer layers prepared by pulsed laser deposition

Abstract

We report on the effect of Ni doping on the tunability and dielectric loss of perovskite Ba0.6Sr0.4TiO3 (BST) thin films with the change of Ni doping concentration. BST thin films were deposited on Pt/Ti/SiO2/Si and La0.5Sr0.5CoO3 (LSCO)/Pt/SiO2/Si substrates by pulsed laser deposition. At an applied electric field of 143 kV/cm, the tunability values of BST films grown on Pt and LSCO/Pt were 12.6 and 62.8% at 100 kHz, respectively. The Ni doping effects were studied for BST thin films grown on LSCO buffer layer. With 1% Ni-doped BST thin films, results gave a tunability of 54.2%, a loss tangent as low as 0.0183, and a figure of merit of about 30. This work demonstrates a potential use for 1 mol % Ni-doped BST thin films in tunable microwave devices. (C) 2003 The Electrochemical Society.