Ion transport study of mechanically-milled amorphous AgI-Ag2O-V2O5 fast ionic conductors

TL;DR

This study investigates the structural and electrical properties of mechanically-milled amorphous AgI-Ag2O-V2O5 ionic conductors, revealing temperature-dependent conductivity behavior and the applicability of the Jonscher power law.

Contribution

It provides new insights into the ion transport mechanisms in mechanically-milled amorphous ionic conductors within the glass forming region.

Findings

Amorphisation is limited to compositions within the glass forming region.

Samples exhibit high agglomeration and are X-ray amorphous.

AC conductivity follows the Jonscher power law with two distinct Arrhenius regions.

Abstract

The structural and electrical characterizations of mechanically-milled (MM) amorphous fast ionic conductors (a-FICs), viz. xAgI (100-x)[0.67 Ag\_2 O-0.33V\_2O\_5] (x = 40, 50, 55 and 70) have been reported. The amorphisation is restricted only to the compositions which are well within the glass forming region and all samples are found to be highly agglomerated and X-ray amorphous in nature. The frequency dependent ac conductivity, \sigma'(\omega), of the amorphous samples investigated in the frequency range 5Hz -13 MHz and temperature range 100- 350 K shows a dc conductivity regime at low frequencies and a dispersive regime at higher frequencies. The spectra can be described by the Jonscher power law (JPL), \simga'(\omega) = \sigma\_dc +A(T) \omega\_n. However, the values \sigma\_dc (T) and A(T) both show two distinct Arrhenius regions and n (< 1) is found to be temperature dependent, i.e., decreasing with increasing temperature.