Raman study of SrBi₂Ta₂O₉thin films

Abstract

Abstract Thin films of SrBi2Ta2O9 (SBT) were deposited on Si using Sol-Gel technique. The thicknesses of the films 200 nm (SBT2) and 400 nm (SBT4), respectively. SEM were studies showed most of the grains in the film are smaller than 0.1 μ. FTIR reflectivity measurements of the samples showed bands around 1260, 936(for SBT2), 955(for SBT4), 770, 600 cm−1. Micro Raman spectra shows bands corresponding to the SBT materials, but some frequency shifts and broadening were observed. Particularly, the band around 818 cm−1, which corresponds to a stretching of the TaO6 octahedron, was found to change from 785 to 827 cm−1. This change seems to be related to the Ta-O bond length.