Synthesis and Characterization of SrTiO3 Doped with Bi(CH3COO)3

Abstract

Synthesis of Strontium Titanate (SrTiO3) doped with Bismuth Acetatem (Bi(CH3COO)3) has been successfully carried out with varying concentrations of 0%; 0.5%; 1%; and 1.5% impurity in weight percent. The concentrated solution was dripped onto a P- type silicon substrate (1 0 0) using the Chemical Solution Deposition (CSD) method and spin coating technique. Annealing process was carried out with a temperature increase of 1.67oC/minute and held at 850oC for 8 hours and then cooled to room temperature for 12 hours. The film thickness was determined by the volumetric method, resulting in values of 3.9 μm, 4.3 μm, 4.7 μm and 5.1 μm. The analysis of optical properties with the Kubelka-Munk function for the direct transition results a band gap of 3.46 - 3.56 eV. Analysis of the XRD results was carried out using the Cramer-Cohen method and obtained lattice parameters (a=b=c) of Strontium Titanate (SrTiO3) doped with Bismuth Acetate (Bi(CH3COO)3) with various concentrations of 0%; 0.5%; 1%; and 1.5% are 3.835 Å, 3.837 Å, 3.909 Å, 3.913 Å respectively with a cubic crystal structure. This is because the ionic radius of bismuth (1.32 Å) is larger than that of strontium (1.17 Å), so bismuth will replace strontium in thin films. This replacement causes the lattice parameter values to increase, and effects the XRD spectral curve at the preferred peak (1 1 0) shift to the left. This shows that the doping bismuth has entered the strontium host.