The structural, dielectric and ferroelectric properties of La-modified bismuth titanate thin films prepared by sol-gel process

摘要

Lanthanum modified bismuth titanate (Bi/sub 4-x/La/sub x/Ti/sub 3/O/sub 12/ BLT-10x) ferroelectric thin films were prepared by the sol-gel method using tetrabyl titanate, bismuth nitrate and lanthanum nitrate. Polycrystalline BLT-5 thin films were obtained at relatively low annealing temperatures of 600/spl sim/650/spl deg/C. The intensity of XRD peaks of BLT-5 thin films increased with increasing annealing temperature. Typical coercive electric field (E/sub c/.) and remnant polarization (P/sub r/) for BLT-5 thin films annealed at 650/spl deg/C were E/sub c/=67 kV/cm and P/sub r/ = 11.2 /spl mu/ C/cm/sup 2/, respectively. The effect of heat treatment on the crystalline and electrical properties of BLT-5 thin films was also discussed.