Sol-Gel Synthesis and Characterization of Ba1-xGdxTiO3+δ Thin Films on SiO2/Si Substrates Using Spin-Coating Technique

Abstract

Ba_1-xGd_xTiO_3+δ, at x = 0, 0.05, 0.1, 0.15, 0.2, (BGT) thin films have been fabricated on SiO₂/Si substrate using Sol-Gel method. The microstructure and surface morphology of the fabricated films have been investigated using X-ray diffraction (XRD) and atomic force microscopy (AFM). The XRD results show that the fabricated films are crystalline with perovskite structure. There is a shifting of the preferred peak at 31.5^o to a higher angle as the doping ratio increases suggesting a distortion lattice exists in the films, which could be due to the substitution of Gd³⁺ ions into Ba-site. The decreasing of lattice constants confirms the substitution of Gd³⁺ in BaTiO₃ lattice structure. The microstrain and dislocation density are found to be increased with the increase of Gd³⁺ doping, which attributed to the reduction of lattice volume that due to the ionic size mismatch effect. The AFM results show decreasing trend in both average grain size and roughness parameters. Therefore, the microstructure and surface morphology of BGT samples is strongly dependent on the Gd³⁺ doping concentration that mainly due to the difference ionic radius substitution.

DOI: http://dx.doi.org/10.5755/j01.ms.23.1.13954