Dielectric Characterization of Barium strontium titanate (BST) Films Prepared on Cu Substrate By Aerosol Deposited Method

Abstract

Polycrystalline barium strontium titanate (Ba_xSr_1-xTiO₃, BST) films were directly prepared on copper substrate using aerosol deposition method (ADM) at room-temperature. We investigated the relationships between their properties such as dielectric constant and tunability, and Ba content in Ba_xSr_1-xTiO₃ (x=1.0, 0.6, 0.4) films. At the frequency of 100 kHz, the dielectric constant of the as-deposited BST film were 100, 201, and 72 at x = 1.0, 0.6, 0.4, respectively. After annealing in N₂ gas ambient at 600degC for 10 min, the dielectric constant and dielectric loss of BST (x=0.6) film were 380 and 2.0 x 10^-3 at 100 kHz, respectively. Moreover, BST (x=0.6) film even showed a high tunability of 30 % at an applied electric field of 300 kV cm^-1.