Dirubidium fluorotrioxophosphate, Rb2PO3F, at 290 and 130 K, and dicaesium fluorotrioxophosphate, Cs2PO3F, at 240 and 100 K.
The structure of Rb2PO3F was determined at 290 and 130 K, while that of Cs2PO3F was determined at 240 and 100 K. Both compounds belong to the beta-K2SO4 family. The structure analysis did not reveal signs of a phase transition in either compound. Crystal chemical considerations do not favour the presence of a phase transition in either Rb2PO3F or Cs2PO3F. However, glass-like phase transitions were observed by differential scanning calorimetry in slightly humid samples at 175 and 177 K for Rb2PO3F and Cs2PO3F, respectively, but were not observed in well dried samples. The bond distances are normal and Cs2PO3F is twinned.
Fábry
Jan
J
Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 182 21 Praha 8, Czech Republic. fabry@fzu.cz
Dusek
Michal
M
Fejfarová
Karla
K
Krupková
Radmila
R
Vanek
Premysl
P
Císarová
Ivana
I