Intermediate Range Structure in Ion-Conducting Tellurite Glasses

TL;DR

This paper reports novel oscillatory modulations in ac conductivity spectra of tellurite glasses at MHz frequencies, linked to their fractal intermediate-range structure, with temperature-dependent effects near the glass transition.

Contribution

It introduces the first observation of MHz-range oscillations in tellurite glasses and models their origin as due to fractal intermediate-range structural features.

Findings

Oscillatory modulations are more pronounced at lower temperatures.

Modulations diminish near the glass transition temperature.

A minimal model links these effects to the fractal structure of the glass.

Abstract

We present ac conductivity spectra of tellurite glasses at several temperatures. For the first time, we report oscillatory modulations at frequencies around MHz. This effect is more pronounced the lower the temperature, and washes out when approaching the glass transition temperature $T_g$. We show, by using a minimal model, how this modulation may be attributed to the fractal structure of the glass at intermediate mesoscopic length scales.