TRANSPORT-PROPERTIES OF ZRF4-BAF2-LAF3-LIF, ZRF4-BAF2-LAF3-NAF GLASSES

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 ZrF4BaF2ThF4LiF system, it is proposed that in the low concentration Li domain Li/F {greater-than or approximate} 0.07), they properties result from mixed contributions of mobile Li+ and F- ions and for high Li concentrations (Li/F {greater-than or approximate} 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. © 1990.