The Dielectric Tunability of Fe-Doped Pb0.3Sr0.7TiO3 Thin Films Prepared by Sol-Gel Method

Abstract

Fe-doped Pb0.3Sr0.7TiO3 (PST) thin films have been fabricated on Pt/Ti/SiO2/Si substrates with sol–gel method. The structure and surface morphology of Fe-doped PST thin films were investigated as a function of Fe concentration by x-ray diffraction (XRD) and atomic force microscopy (AFM). The dielectric measurements were conducted on metal-insulator-metal capacitors at the frequency from 100 Hz to 1M Hz at room temperature. It’s found that the dielectric constant, dielectric loss and tunability of Fe-doped PST films decreased with the increase of Fe content. The effects of Fe doping on the microstructure, dielectric and tunable properties of thin films were analyzed. Though the undoped PST thin film exhibited the highest dielectric constant of 2011 and the largest tunability of 76%, the 6 mol% Fe doped PST thin films had the highest figure of merit (FOM) of 17.9 for its lowest dielectric loss.