F− ion conductivity and diffusion properties in ZrF4-based fluoride glasses with various NaF concentrations (0 ⩽ xNaF ⩽ 0.45)

摘要: Abstract Selecting two series of ZrF4-based fluoride glasses containing at the same time BaF2 and NaF network modifiers a third with only, an investigation electrical diffusion properties has been undertaken as function xNaF in wide concentration domain (0 ⩽ 0.45). The ac conductivity data have analysed by complex modulus formalism hopping mechanism for transport these materials is suggested. 23Na 19F NMR investigations shown that Na+ ions do not participate charge carriers conduction mechanisms are due only to motions mobile F− ions. Mobility number scale increase when xBaF2 increases, result agreement composition dependence long range. Experimental points representative log σ473 K ΔEσ studied located on both sides “master” curves involving minimum activation energy maximum ∼- 0.30. Variation decoupling index, Rτ(Tg), whole composition. On contrary, variation Kohlrausch parameter, β, more difficult analyse may be explained coupling model ≲ 0.15. various parameters discussed glass