Large ferroelectric response in Bi4−xNdxTi3O12 films prepared by sol–gel process

Neodymium-substituted Bi4Ti3O12 (i.e., Bi4−xNdxTi3O12) were synthesized by sol–gel process for different compositions. Thin films were deposited on Pt (i.e., Pt/TiO2/SiO2/Si) substrate by spin coating. Materials were characterized by x-ray diffraction and Raman spectroscopy. This study indicates that the material makes a solid solution for the compositions: x=0.00, 0.26, 0.46, 0.75, 0.85, 1.00, and 2.00, where an Nd ion replaces the Bi site. The prominent effect of Nd substitution is observed in low-frequency Raman modes. Sol–gel derived thin films of Bi3.54Nd0.46Ti3O12 on a Pt substrate and postannealed at 700 ° C were tested for ferroelectric response which showed high remnant polarization (Pr=25 μC/cm2).