Structure of chalcogenide glasses by neutron diffraction

TL;DR

This study investigates the atomic structure of Ge-Se glasses doped with Ag using neutron diffraction, revealing details about local bonding environments and the effects of doping on short-range order.

Contribution

It provides new insights into the structural changes in Ge-Se glasses upon Ag doping through neutron diffraction and numerical simulations.

Findings

Presence of GeSe4/2 tetrahedra and Se-Se bonds confirmed

Ag atoms linked to Se in a triangular environment

Correlation distances and coordination numbers vary with temperature

Abstract

The purpose of this work is to study the change in the structure of the Ge-Se network upon doping with Ag. The total structure factor S(Q) for two samples has been measured by neutron diffraction using the two-axis diffractometer dedicated to structural studies of amorphous materials, D4, at the Institut Laue Langevin. We have derived the corresponding radial distribution functions for each sample and each temperature, which gives us an insight about the composition and temperature dependence of the correlation distances and coordination numbers in the short-range. Our results are compatible with the presence of both GeSe4/2 tetrahedra and Se-Se bonds. The Ag atoms are linked to Se in a triangular environment. Numerical simulations allowing the identification of the main peaks in the total pair correlation functions have complemented the neutron diffraction measurements.