Heat capacity and T-p phase diagram of Cs2NH4GaF6 elpasolite

Mikhail V. Gorev (1) , Igor N. Flerov (1) , Alain Tressaud (2) , Alexander I. Zaitsev (1) , Etienne Durand (2)

1 L.V. Kirensky Institute of Physics
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Cs2NH4GaF6 prepared by solid-state reaction exhibits at room temperature a cubic FmView the MathML sourcem elpasolite structure with a0=9.167 Å. Calorimetric measurements have shown the presence of a first order phase transition at T0=161 K. Pressure dependence of the phase transition temperature has been studied by DTA under pressure. The data are analyzed in the framework of orientational disordering of [NH4]+ and [GaF6]3− ions.

Mots clés: Fluorides; Elpasolite; Cryolite; Structural phase transition; Adiabatic calorimetry; Pressure

Domaines: Matériaux

Mikhail V. Gorev, Igor N. Flerov, Alain Tressaud, Alexander I. Zaitsev, Etienne Durand. Heat capacity and T-p phase diagram of Cs2NH4GaF6 elpasolite. Solid State Sciences, 2002, 4 (1), pp.15-18. ⟨10.1016/S1293-2558(01)01217-1⟩. ⟨hal-00705855⟩