Structure and dielectric properties of Bi-doped Ba0.6Sr0.4TiO3 thin films fabricated by sol-gel method

Abstract

An alkoxide-based sol-gel method was used to fabricate Ba0.6Sr0.4TiO3 thin films doped by Bi from 5 to 20 mol% on a Pt/Ti/SiO2/Si substrate. The structural and dielectric properties of BST thin films were investigated as a function of Bi dopant concentration. The dielectric properties of the Bi doped BST films were strongly dependent on the Bi contents. The dielectric constant and dielectric loss of the films decreased with increasing Bi content. However, the leakage current density of the 10 mol% Bi doped Ba0.6Sr0.4TiO3 thin film showed the lowest value of 5.13 x 10(-7) at 5 V The figure of merit (FOM) reached a maximum value of 32.42 at a 10 mol% Bi doped Ba0.6Sr0.4TiO3 thin films. The dielectric constant, loss factor, and turtability of the 10 mol% Bi-doped Ba0.6Sr0.4TiO3 thin films were 333, 0.0095, and 31.1%, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.