Pyrochlore-like compounds derived from antimonic acid
Abstract
Highly crystalline antimonic acid, H2Sb2O6·1.5H2O (CAA) with a pyrochlore-like structure has been ion-exchanged with Fe3+ and Cd2+ to form H1.34Fe0.22Sb2O6·1.5H2O (CAA/Fe) and H0.73Cd0.635Sb2O6·1.5H2O (CAA/Cd) phases. Thermal decomposition of these phases was studied by XRD, FTIR, TG, DSC and SEM. The final products, obtained by the thermal treatment of CAA/Fe and CAA/Cd at 1100 °C, for 2 h, were FeSbO4 and Cd2Sb2O7 –x, respectively. The chemical homogeneity and phase purity for these compounds, and the temperature and time for reactions indicate that the use of adequate precursors has advantages, in comparison to conventional solid–solid methods involving mixtures of oxides.