Soft-chemical derived Bi2O3–ZnO–Ta2O5 nanopowder and ceramics

In this paper, the synthesis of bismuth zinc tantalate pyrochlore (Bi1.5ZnTa1.5O7, α-BZT) by a soft-chemical method, based on the polymeric precursors, was investigated in order to obtain chemically homogeneous powders. The pyrochlore phase was investigated by X-ray diffraction, UV–vis and Raman spectroscopy. The study of α-BZT formation reveals that, at 600 °C, a single-phased nanopowder was obtained without any detectable intermediary or secondary phases. The morphology of the powders was examined by scanning electron microscope; the mean size distribution was measured by low angle laser light scattering. Both measurements showed a nanoscaled powder with large soft agglomerated clusters. The optical gap, obtained from the UV–vis spectra, ranged from 2.5 to 3.2 eV for the powders treated from 500 to 900 °C, respectively.