Temperature-induced phase transformations of the "glaserite" type zirconosilicate Na3HZrSi2O8 center dot 0

0393992 - ÚACH 2014 RIV GB eng J - Journal Article
Kostov-Kytin, V. - Nikolova, R. - Kerestedjian, T. - Bezdička, Petr
Temperature-induced phase transformations of the "glaserite" type zirconosilicate Na3HZrSi2O8 center dot 0.
Materials Research Bulletin. Roč. 48, č. 6 (2013), s. 2029-2033. ISSN 0025-5408. E-ISSN 1873-4227
Institutional support: RVO:61388980
Keywords : inorganic compounds * Thermogravimetric analysis (TGA) * X-ray diffraction * crystal structure
Subject RIV: CA - Inorganic Chemistry
Impact factor: 1.968, year: 2013

DTA-TG and powder XRD analyses are used to study the occurring upon heating structural transformations of the "glaserite" type zirconosilicate Na3HZrSi2O8 center dot 0.4H(2)O. The title compound undergoes energetically favored irreversible topotactic dehydration within the temperature range 200 and 400 degrees C. Essential structural transformations occur only after 700 degrees C, however, the phase composition of the run-product strongly depends on the conditions of thermal treatment. In all cases the predominant phase at 1000 degrees C is the NASICON type zirconosilicate - Na4Zr2Si3O12. The concomitant compound is either Na2SiO3 or the parakeldyshite synthetic analog - Na2ZrSi2O7. The mechanism of structural transformation and certain structural relationships are discussed in terms of the crystal chemical peculiarities of the initial compound and the run-products.
Permanent Link: http://hdl.handle.net/11104/0222324