Measurement of dielectric properties of ferroelectric Ba1-xSrxTiO3 thin films

Ferroelectric Ba0.6Sr0.4TiO3 (BST) thin films were grown on (La0.5Sr0.5)CoO3/Pt/Ti/SiO2/Si and MgO(100) substrates by the pulsed laser deposition method. The grain orientations of the films were controlled by the substrate orientation. Microwave properties of BST thin films have been measured using both metal-ferroelectric-metal (MFM) trilayer capacitor and metal-ferroelectric-dielectric (MFD) interdigital capacitor structure with frequency range upto 4 GHz at room temperature, and compared with the dielectric properties data measured in the frequency from 100 Hz to 1 MHz. Large frequency dependent dispersions and grain orientation dependent dielectric properties were found in both structures, MFM and MFD capacitors.