Four allotropic forms were found, for this ternary fluoride, by using microcalorimetry, high-temperature X-ray diffraction, optical and electrical measurements. Alternating-current conductivity data were analyzed in the Z*, M* and ε* formalisms, and the conductivity relaxation parameters were determined. The conductivity was of Arrhenius-type on each side of a transition, at 488K, which was very close to the Curie temperature of 480K. A conductivity jump of about one decade was observed at the Curie point, and the transition was of ionic-superionic type.

Phase Transitions and Ionic Transport in K3InF6. J.M.Réau, K.Aliouane, M.Hamadène, A.Guehria, M.El Omari, J.Grannec, J.Ravez: Solid State Ionics, 2000, 127[3-4], 301-8