Ionic mobility in LixK1 − xSn2F5 (x = 0–0.15) solid solutions obtained by mechanochemical synthesis

Abstract

The solid solutions LixK1 − xSn2F5 (x = 0–0.15) were synthesized by the mechanochemical method. According to XRD and 19F MAS NMR data, the samples are isostructural to KSn2F5, which has superionic properties. The fluoride-ion jump frequency at a given temperature depends on the LiF concentration and is highest for x = 0.02. The amount of the mobile lithium ions at 420 K is maximal for Li0.075K0.925Sn2F5. Two types of fluorine positions with different jump frequencies are present in the structure of the compounds. Occupancy factors of the positions depend on the dopant concentration.