Micro- and Nanocomposites of Barium Zirconate Incorporated in Polymer Matrix

The radiation properties and the crystalline structure of hybrid composites based on polymer matrices—polystyrene, poly-3,4-ethylenedioxithiophene, polyphenylacetylene, polyvinyl alcohol and micro- (d < 10 µm) and nanocrystals (d < 50 nm) of BaZrO₃ have been studied using luminescent spectroscopy, X-ray analysis and FTIR-spectroscopy. A strong cathodoluminescence in pristine BaZrO₃ micro- and nanocrystal powders aneled at 500, 700, and 900 °C is observed in temperature range 80–293 K. Spectrum can be decomposed into three bands with maxima at E = 2.99, 2.69 and 2.2 eV. It was also found that composites of probed polymers (polyphenylacetylene, poly-3,4-ethylenedioxithiophene, and polyvinyl alcohol) do not produce sufficient effect on the luminescent spectra of nanocrystals. In the case of polystyrene–BaZrO₃ composites, the cathodoluminescent spectrum is modified: both the low- and high-energy bands (near 4 eV) appear, together with a significant reduction in the cathodoluminescence intensity. A decrease of the lattice parameter “а” for BaZrO₃ phase in the composite and the modification of cathodoluminescence spectra indicate changes in the nanocrystalline structure induced by the polymer. Interaction of BaZrO₃ nanocrystals with polymer matrix was confirmed by FTIR spectroscopy.