Dielectric Properties Of Barium Strontium Titanate Thick Films Prepared By Electrophoretic Deposition

摘要

Ba_xSr_(1-x)TiO_3 (x = 0.5,0.6,0.7) thick films were prepared by electrophoretic deposition (EPD) technique on platinum metallic foils using BaTiO_3 and SrTiO_3 nanoparticles with different molar proportion of 1:1,3:2 and 7:3, respectively. An isostatic pressure method was used to increase density of the thick films before high temperature sintering. Microstructures of the deposited films were examined with XRD and SEM techniques. Porosity of the thick films decreased after the isostatic pressure process. The Ba_(0.5)Sr_(0.5)TiO_3 thick films of 10μm, 15 μm and 20 μm showed a tunability of 28.8%, 33.3% and 33.9%, respectively, at room temperature and at a biasing field of 2 kV/mm. The dielectric constant was from 2138 to 3446 and dielectric loss was from 0.016 to 0.011 at zero bias field at 10 kHz. The temperature dependence of dielectric constant was also measured and the effect of porosity and thickness on the electrical performance of the thick films was discussed.