Pre-Crystallization Criteria and Triple Crystallization Kinetic Parameters of Amorphous–Crystalline Phase Transition of As40S45Se15 Alloy

Meshal Alzaid,N M A Hadia,Mohamed N Abd-El Salam,E R Shaaban,Ammar Qasem

doi:10.1007/s10904-021-02080-4

Abstract

This framework focuses mainly on a detailed study of the pre-crystallization criteria that characterize the As40S45Se15 glassy alloy in various heating rates ranging from 5 to 40 (K/min) by Differential Scanning Calorimetry (DSC). These criteria aim to clarify the relationship of the tendency of glass-forming by the heating rate for the investigated glassy alloy. The crystallization parameters were calculated using different methods.The activation energy of crystallization Ec(χ) as a function of conversion (χ) was obtained using the iso-conversional models of Flynn–Wall–Ozawa (FWO), Starink and Kissinger–Akahira–Sunose (KAS). The results show a slight increase of Ec(χ) with conversion (χ) which accounts for a single-step mechanism controlling the crystallization process. Moreever, the conversion dependence of the Avrami exponent n(χ) show an increase with conversion (χ), average values of n(χ) can be accounted for two and three-dimensional crystal growth with heterogeneous nucleation. On the other hand, the fitting of the experimental DSC data to the calculated DSC curves indicated that the crystallization process of the studied glasses cannot be satisfactorily described by the Johnson–Mehl–Avrami (JMA) model. On the contrary (SB) model is more suitable to describe the crystallization process for the studied of As40S45Se15 Alloy. Finally, the crystalline structure of the study sample was recognized by X-ray diffraction (XRD) and electron scanning microscope (SEM).

Highlights

Due to their promising optical, thermal, and electrical properties, chalcogenide substances have achieved a great deal in the research works
The observation of one endothermic peak for the melting phenomena could be attributed to the formation of one phase through the heating which is confirmed by the X-ray diffraction (XRD) analysis
The results shows the strong heating rate dependence of the activation energy

Summary

Introduction

Due to their promising optical, thermal, and electrical properties, chalcogenide substances have achieved a great deal in the research works. This enables optoelectronic implementations, e.g. switching systems, IR laser diodes, optical fibers, optical transmission media, correctable phase changes, and optical records [1, 2]. The crystallographic state of the solid is restricted to a few frame structures, while the amorphous Chalcogenide is meaningful in amorphous systems regarding the efficacy as excellent materials for optical ultrafast nonlinear devices such as demultiplexer (or demux), wavelength adapters and Kerr optical shutters [3]. The structure of chalcogenide components has been extensively studied in binary compositions, whether bulk or thin-film. Several binary substances can be formulated by attaching one of the chalcogens with another element like As, Sn, Ag, In, Pb, Al...etc [2]

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Results

Conclusion