Electrical conductivity of lithium-sodium tetragermanate in amorphous state

Abstract

The glass of lithium-sodium tetragermanate LiNaGe4O9 was prepared by rapid quenching the melt. The structure of the glass was characterized by X-ray phase analysis. Electrical conductivity σ was measured in AC field (f = 1 kHz÷1 MHz) in the interval Т = 300÷900 K. It was shown that at T > 550 K the typical values of the glass σ were at least one–two orders of magnitude higher than in the single crystal. Ionic conductivity in disordered amorphous and ordered crystalline states was discussed by accounting the structure of lithium-sodium tetragermanate. The main contribution to conductivity in LiNaGe4O9 glass was associated with thermally activated motion of Li ions which were weakly bound to Ge-O structuralframework.