Preparation and study of structural properties of zinc-doped barium stannate

In the present work, we report the results of the influence of the Zn ions that partly substitute the Ba ions in the barium stannate (Ba1-xZnxSnO3, where x = 0 - 0.5), on the structural properties. With the view to obtain a porous and finer structure, thus providing a high specific surface, these materials were obtained through the precursor method of combustion (co-precipitation in a colloidal environment, and combustion), followed by heat treatments. The phase composition and morphology were studied through XRD and SEM techniques. The pure sample, as well as that with the substitution x < 0.1, are single phased after 40 minutes sintering at 1000 degrees C. For substitutions with x >= 0.1 secondary phases appear, but the structure becomes finer and the area of specific surface increases for x = 0.2, remaining then constant with the increasing doping with zinc ions up to x = 0.5. The sample with the substitution x = 0.2-0.5 is characterized by a very fine structure (similar to 300 nm) and an effective porosity (21%). These materials obtained through this new method are quite promising for the realization of quality humidity or gas sensors.