Ferroelectric, dielectric, and optical properties of Nd-substituted Bi4Ti3O12 nanoparticles synthesized by sol-gel method

This paper reports the synthesis of neodymium substituted bismuth titanate nanoparticles (BNdT) for ferroelectric random access memory (FeRAM) based applications using sol-gel route. X-ray diffraction pattern showed that the BNdT nanoparticles exhibited perovskite structure with orthorhombic phase. The microstructure of the BNdT nanoparticles showed that the grains were in spherical structure with a bi-modal distribution of spheres. Dielectric constant and dielectric loss of BNdT nanoparticles were measured in the frequency range 100 Hz to 100kHz. Nd-substituted BNdT nanoparticles showed the high remanent polarization (Pr=33.2 μC/cm2, Ec=62.5 kV/cm) than pure bismuth titanate (BT) (Pr=14.6 μC/cm2, Ec=182.8 kV/cm) ideal for FeRAM based applications. The occurrence of red shift in photoluminescence (PL) spectrum is considered to be due to the isomerisation that may occur from the heating of samples.