Electrical Characterization and Microstructures of La-Doped Bi4Ti3O12 Thin Films

Abstract

La-doped bismuth titanate (Bi4-xLaxTi3O12: BLT) and pure Bi4Ti3O12 (BIT) thin films with random orientation were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed rod-like grains with random orientation. La-doping into BIT caused a large shift of the Curie temperature ( TC ) from 675°C to lower temperature and a improvement in dielectric property. The experimental results indicated that La doping into BIT also result in a remarkable improvement in ferroelectric property. The Pr and the Ec values of the BLT film with x=0.75 were 20 μC/cm2 and 82kV/cm, respectively.