Enhanced Ferroelectric Properties of Gd- Substitution BiFeO3 Thin Films Prepared by Sol-Gel Process

Abstract

BiFeO3 and Bi1−xGdxFeO3 (BGFO)(x = 0.05, 0.10, and 0.15) thin films were deposited on Pt/Ti/SiO2/Si substrates by a sol–gel process. X-ray diffraction results show that a gradual phase transition from rhombohedral to pseudotetragonal structure may occur in BGFO films with the increase of Gd content. We observed a substantial increase in the remnant polarization (Pr) with Gd substitution and obtained a maximum value of 72.6 μC/cm2 by 0.05 molar Gd incorporation. The leakage current behavior at room temperature of the films was studied and it was found that the leakage current density decreased from 10−6 to 10−9 A/cm2 for 0.05 molar Gd-substituted films under a field 150 kV/cm. The reduction of dc leakage current of Gd -substituted films is explained on the basis of relative phase stability and improved microstructure of the material.