Calorimetric and x-ray diffraction studies of the (NH4)3WO3F3 and (NH4)3TiOF5 perovskite-like oxyfluorides |
| |
Authors: | I N Flerov M V Gorev V D Fokina A F Bovina and N M Laptash |
| |
Institution: | (1) Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russia;(2) Institute of Chemistry, Far East Division, Russian Academy of Sciences, pr. Stoletiya Vladivostoka 159, Vladivostok, 690022, Russia |
| |
Abstract: | The heat capacity and unit cell parameters of the (NH4)3WO3F3 and (NH4)3TiOF5 perovskite-like oxyfluorides were measured in the temperature interval from 80 to 300 K; the existence of two and one phase
transitions in these compounds, respectively, was demonstrated, and their thermodynamic parameters were determined. The effect
of a hydrostatic pressure of up to 0.5 GPa on the phase transition temperatures was studied. Triple points and high-pressure
phases were found in the T vs. p diagrams. An analysis of entropy changes suggests that all the structural transformations revealed are associated with the
ordering of structural blocks.
__________
Translated from Fizika Tverdogo Tela, Vol. 46, No. 5, 2004, pp. 888–894.
Original Russian Text Copyright ? 2004 by Flerov, Gorev, Fokina, Bovina, Laptash. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|