Dielectric properties of SrTiO3 thin films grown on various perovskite electrodes by pulsed laser deposition

The dielectric properties of SrTiO3 (STO) thin films deposited on LaAlO3 (LAO) substrates with various perovskite conducting layer including YBa2Cu3O7 (YBCO), SmBa2Cu3O7 (SmBCO), GdBa2Cu3O7 (GBCO) and SrRuO3 (SRO) as bottom electrode in a parallel-plate capacitor configuration were evaluated. The lattice mismatch between STO and different electrode materials varies markedly, but the dielectric constants of the STO films were not much different for different bottom electrodes. However, lower dielectric loss was observed in STO films on SRO electrodes. Under the optimum deposition conditions the tunability was large and the loss tangent was in the range of 0.001–0.01 at 1 kHz and zero bias field.