G.R. Štrbac

Analysis of thermal processes in Cux(AsTe)100?x glasses

Chalcogenide glasses are promising materials for application in fiber optics and all-optical switching devices at telecommunication wavelengths, due to both their high transparency in the infrared region and their nonlinear refractive index. In this paper we present and discuss the results of the analysis of the processes that occur during the thermal treatment of the Cux(AsTe)100?x glass system, x?=?5 and 20?at.%. Our analysis is based on differential scanning calorimetry (DSC) curves, recorded in non-isothermal measurement conditions in temperature intervals of 300?770?K, at a heating rate of ??=?10?K?min?1. Samples with x?=?20?at.% are thermally treated at four different heating rates in order to implement kinetic analysis of the processes. The activation energy of the crystallization Ec is determined by the Kissinger and Mahadevan methods. The characteristic parameters of the crystallization process are determined using the Matusita method. We conclude that nucleation occurs in three dimensions and within the volume. The amorphous character of the as-prepared samples is verified by x-ray. A diffractogram of the glass sample with x?=?20?at.%, which was annealed at a temperature close to the crystallization temperature established by the DSC analysis, shows that structural units of copper with arsenic and copper with arsenic and telluride are formed within the amorphous matrix.

Modification of some Optical and Mechanical Properties of Amorphous As-S-Se Thin Films by Copper Introduction

Abstract. In this research experimental investigation of the influence of copper introduction on some relevant parameters in As-S-Se amorphous thin films is performed. Copper is introduced into As2(S0.5Se0.5)3 amorphous thin film in concentration of 3 at.%. Samples of As2(S0.5Se0.5)3 and Cu3(As2(S0.5Se0.5)3)97 amorphous thin films are prepared by the vacuum thermal evaporation technique from previously synthesized bulk samples. Envelope method is applied for the determination of the optical constants, using the transmission and reflection spectra. The dispersion of the refractive index is discussed in terms of the single oscillator model proposed by Wemple–DiDomenico. Values of absorption coefficients in the high absorption region are discussed according to Taucs law.Instrumented indentation testing is performed, using the Berkovich geometry indenter, for obtaining the value of nano-hardness.All the determined parameters have shown the increase with introduction of copper into amorphous thin film.

High-Temperature X-Ray Analysis of the Chalcogenide Glasses in the Multicomponent Sb-As-S-Se-I System

The elements of structural network of the five‐component chalcogenide glasses from the pseudo‐binary system (As2Se3)100−x(SbSI)x have been investigated by high‐temperature X‐ray powder diffraction analysis. Appearance of a large number of structural units in the crystallization processes above glass transition temperature Tg was observed. The DSC experiments shows that the temperature regions of crystallization translates to lower temperatures with increasing SbSI content. Structural unit of SbSI, which in the monocrystal form is a ferroelectric, exists in materials with x⩾50 at. %.