Preparação e caracterização de pós e filmes finos de BaTiO3 sintetizados via método Pechini

Abstract

In recent years the use of barium titanate (BaTiO3) in ceramics industry technology and optoelectronic devices has increased due to their ferroelectric, thermoelectric, piezoelectric and optical properties. The objective of this study was to synthesize and characterize amorphous powders and thin films of barium titanate (BaTiO3), through the Pechini method. These powders were characterized via thermal analysis (TG / DSC) and X-Ray Diffraction (XRD). The temperature employed in the heat treatment of the powders was 400° C to 800° C depending on the sample, for 10 hours. Structural analysis of the XRD revealed an increase in the spectral line which can be observed in some diffractograms patterns near to the angle of 30° 2θ, suggesting a higher crystallinity and an increase in crystallite size caused by the increase of the calcination temperature. These tests also indicate the presence of BaCO3 and was also observed the formation of only one peak at 45° 2θ, suggesting the formation of cubic phase with titanate. Through the results obtained from the XRD the grain size was calculated, whose dimensions gotten were approximately 50 nm. BaTiO3 thin films were deposited by dip coating. These films were studied by atomic force microscopy (AFM). This technique allowed us to observe clusters of particles in every film. The surface of these films presented significant changes in roughness with increasing temperature heat treatment of films.