Sol–gel synthesis of Ta2O5–SiO2 composites from tantalum(V) chloride and tetraethyl orthosilicate in ethanol

Resumo

Ta₂O₅–SiO₂ composites containing 10, 50, and 90 wt % SiO₂ have been prepared by a sol–gel process in ethanolic solutions of tantalum(V) chloride with tetraethyl orthosilicate. The physicochemical aspects of their formation have been studied by IR spectroscopy, X-ray diffraction, X-ray microanalysis, and thermal analysis in combination with mass spectrometry. The results demonstrate that the SiO₂ content of the Ta₂O₅–SiO₂ composites influences the uniformity of the tantalum and oxygen distributions on the surface of the materials and that heat-treatment conditions influence their crystallinity.