The isomorphous acid salts α-Zr(HPO4)2 · H2O, α-Ti(HPO4)2 · H2O and α-Zr(HAsO4)2 · H2O Comparative thermochemistry and vibrational spectroscopy

✍ Scribed by Robert C.T. Slade; James A. Knowles; Deborah J. Jones; Jacques Rozière

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 831 KB
• Volume: 96
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(97)00012-x

✦ Synopsis

A set of isomorphous acid salts of ideal general formula wM'~(HXO,), . H,O [o-zirconium phosphate (cx-ZrP), a-titanium phosphate (a-Tip) and o-zirconium arsenate(V) (a-ZrAs)] has been investigated. In the case of o-ZrP, different preparative techniques were used to yield samples of differing crystallinity. Sample characterisation was by X-ray powder diffraction, thermochemical techniques (TG and DSC), and optical spectroscopies (infrared and Raman). Thermochemical findings included (i) phase transitions in anhydrous TiP occur at higher temperature than for ZrP, (ii) condensation of the acid anions at lower temperature for the arsenate than for the phosphates, (iii) dependence of temperatures of thermal events in cx-ZrP on the crystallinity of the material. Bands and lines occurring in the optical spectra of these materials have been discussed and assigned.