Activation properties of Ag-ion conduction in bulk amorphous AgI: estimation from extrapolation of the AgI composition dependence in AgI–Ag₂O–P₂O₅glasses

Abstract

AgI-based fast-ion conducting glasses with very high AgI compositions from the (AgI)x(AgPO3)1−x, (AgI)x(Ag2PO3.5)1−x, and (AgI)x(Ag3PO4)1−x systems were prepared successfully by using a rapid-press quenching and a twin-roller quenching method. The ac dielectric measurements showed common relaxation properties of Ag+-ion conduction in the glasses independently of the species of the glass network formers of AgPO3, Ag2PO3.5, and Ag3PO4, and the activation energies, Δεa, for Ag+-ion conduction were observed to converge upon the same magnitude of ∼26 kJ mol−1 at the AgI composition limit of x = 1. This indicates the formation of amorphous AgI regions in the glasses, and the value of Δεa = 26 ± 1 kJ mol−1 estimated at x = 1 was concluded to correspond to that for bulk amorphous AgI which has never been obtained experimentally.