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Transport properties of ZrF4BaF2LaF3AF (A = Li, Na) glasses

1990; Elsevier BV; Volume: 116; Issue: 2-3 Linguagem: Inglês

10.1016/0022-3093(90)90690-n

1873-4812

J.M. Réau, J. Sénégas, J. M. Rojo, Marcel Poulain, Marcel Poulain,

Microwave Dielectric Ceramics Synthesis

A comparative study of electrical properties of two series of glasses ZrF4(0.62−0.4x)BaF2(0.30−0.5x)LaF3(0.08−0.1x)AF(x) (A = Li, Na) (0 < x < 0.30) has been carried out as a function of AF content. A minimum of ionic conductivity and a maximum of activation energy has been detected when the atomic Li/F ratio is equal to ≅ 0.07. By analogy with the glasses belonging to ZrF4BaF2ThF4LiF system, it is proposed that in the low concentration Li domain Li/F ⪆ 0.07) , they properties result from mixed contributions of mobile Li+ and F− ions and for high Li concentrations (Li/F ⪆ 0.07), they depend only on the Li+ rate. When A = Na, on the contrary, conductivity decreases regularly and activation energy increases with increasing x. The electrical properties result only from the contribution of mobile F− ions. A 23Na NMR study has shown that Na+ ions do not participate in the conductivity.