IONIC-CONDUCTIVITY OF CRYSTALLINE AND GLASSY MG4.5NA7(P2O7)4

In our work single crystals of Mg4.5Na7(P2O7)4 were prepared, pulveriz ed, pressed into pellets and sintered in order to measure the electric al conductivity of polycrystalline specimens. The conductivity was als o measured on glassy specimens obtained by the melting of previously p repared crystals. The electrical conductivities at 25-degrees-C with v alues of the order of 10(-16) OMEGA-1 cm-1 for polycrystalline samples and a value of the order of 10(-14) OMEGA-1 cm-1 for glass, show that the glassy phase of Mg4.5Na7(P2O7)4, because of its greater molar vol ume and loosely packed structure, is a better matrix for ionic motion.