The effect of chemical substitution on the stability of structural phases in Mn1-xZnxSiF6.6H(2)O fluorosilicate hexahydrates has been investigated by means of x-ray diffraction. Under ambient conditions the substitution of heavier Zn atoms for Mn atoms leads to a phase transition between two trigonal phases with the loss of the mirror plane symmetry. It has been found that external pressure and Zn doping have very similar effects on the phase stability of the fluorosilicate hexahydrates, and the established x-T phase diagram mirrors the generalized pressure-temperature phase diagram for the fluorosilicate hexahydrates series. The variety of the phases found and the character of the phase transitions between them are discussed in terms of a qualitative model, which takes into consideration the order-disorder processes in the material.
|Number of pages||8|
|Journal||Journal of Physics: Condensed Matter|
|Publication status||Published - 23 Apr 2001|