Effect of heat treatment on AgI‐rich chalcogenide glasses with enhanced ionic conductivity

Abstract

The glass‐ceramics of AgI‐based electroconductive chalcogenide system was realized using an appropriate heat treatment at a fairly high temperature (Tg + 40°C) and different times ranging from 4 to 20 hours. The crystallization behavior and electroconductive properties of the heat‐treated samples were studied in detail. Transmission study was performed, and the results show that the cut‐off edge of the short wavelength is red‐shifted at prolonged annealing time but remains an excellent transmittance in the mid‐infrared (IR) region. XRD and scanning electron microscopy results indicated that the precipitated crystalline phases are mainly β‐/γ‐AgI. Moreover, a small amount of α‐AgI, which rarely existed at room temperature, is precipitated in the AgI‐rich chalcogenide glass‐ceramics. The ionic conductivity of all glass‐ceramics was enhanced by heat treatment in contrast to that of base glass. Raman analysis exhibited the structure variation in the glass sample after heat treatments. This study provided an observation of crystallization in chalcogenide glass containing large amounts of AgI and be of good guidance to fabricate novel AgI‐based chalcogenide glass‐ceramics that can be candidates in infrared optics and solid electrolyte applications.