Characterization of Ni-Doped BST Thin Films on LSCO Buffer Layers Prepared by Pulsed Laser Deposition

摘要

We report on the effect of Ni doping on the tunability and dielectric loss of perovskite Ba_(0.6)Sr_(0.4)TiO_5 (BST) thin films with the change of Ni doping concentration. BST thin films were deposited on At/Ti/SiO_2/Si and La_(0.5)Sr_(0.5)CoO_3 (LSCO)/At/SiO_2/Si substrates by pulsed laser deposition. At an applied electric field of 143 kV/cm, the tunability values of BST films grown on At and LSCO/At were 12.6 and 62.8 percent at 100 kHz, respectively. The Ni doping effects were studied for BST thin films grown on LSCO buffer layer. With 1 percent Ni-doped BST thin films, results gave a tunability of 54.2 percent, 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 percent Ni-doped BST thin films in tunable microwave devices.