Hydrogen-containing solid solutions of pyrochlore type

Cubic solid solutions of Tlsub(1-x)Hsub(3)MOsub(3+z)xyHsub(2)O pyrochlore type were prepared by interaction of TlNbO3, TlTaO3 and TlNbOsub(3+z) with water and sulfuric acid solutions. The composition was determined from data on chemical, potentiometric and thermogravimetric analysis. Activities of solid solution components and Gibbs energy of exchange reaction were calculated from exchange equilibriums. Dehydration of solid solutions at 85-410 deg C is realized at two stages, at that, the first is reversible and after the second the structure of pyrochlore is destroyed. Tl interaction with oxonium compound was studied on the basis of X-ray analysis data. The results obtained explain the change of lattice period, colour, strong negative deviation from the ideal and S-like form of absorption isotherm