Sci. Agri. 2 (3), 2014: 130-134 © PSCI Publications Scientia Agriculturae www.pscipub.com/SA E-ISSN: 2310-953X / P-ISSN: 2311-0228 DOI: 10.15192/PSCP.SA.2014.2.3.130134 Effect of Sb Addition in GeTeSb Crystallization Abdelhamid Badaoui 1* and Maamar Belhadji 1,2 1. Laboratoire de Chimie des Polymères, LCP, Es-Senia University, Oran, 31000, Algeria 2. Physics Department, Es-Senia University, Oran, 31000, Algeria Corresponding Author email: *aeh_badaoui@yahoo.fr Paper Information A B S T R A C T Received: 20 April, 2014 Accepted: 29 May, 2014 Published: 20 June, 2014 The crystallization process of ternary chalcogenide system GeTeSb is studied using Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD). Antimony Sb effect is discussed. It is found that the Ge15.5-xTe84.5Sbx system presents a double phase separation. The eutectic composition exhibits the same behavior but when thermally treated. The activation energy of the process is calculated according to Kissinger method and the results show that the activation energy varies with Sb content. By X-ray patterns, the identification of the crystallized compounds show that Tellurium Te crystallizes first with 1.8 eV then (Te+GeTe) with 2.1 eV. © 2014 PSCI Publisher All rights reserved. Key words: Switching Materials , Chalcogenide GeTeSb, DSC, Activation energy, Crystallization. Introduction Chalcogenide glasses exhibit photo-induced properties which allow them to be well-used in storage media (S. M. El-Sayed et al. 2007). These glasses have a relatively high atomic mass and weak bond strength resulting in lower phonon energy than other glasses; in consequence, they are highly transparent for light in mid-infrared region (P. Sharma et al. 2009, V. Pamukchieva et al. 2009). Chalcogenide glasses of GeTeSb system have received much consideration because of their interesting applications in modern technology especially in recording domain (F. H. Wu et al. 2003) and the possibility to prepare electrical and storage memories (D. H. Kang et al. 2003, N. Yamada et al. 1987, K. Uchino et al. 1993). In this work, we study some different compositions of GeTeSb system by Differential Scanning Calorimetry (DSC), the activation energies of crystallization are calculated and we show the thermal effect on different X-Ray Diffraction (XRD) traces. The effect of Antimony (Sb) content in the system is discussed. Experimental Setup The preparation of alloys was in two steps. The three elements (99.999 % purity) were weighted in suitable quantities and introduced in a quartz ampoule and sealed in vacuum of 10 -5 Pa. Then, the ampoules were placed in a horizontally rotating oven and annealed at 1000 °C for 3 hours. The ampoules were finally quenched into ice-cold water to avoid crystallization. After breaking the quartz ampoules, amorphous nature of these alloys were verified by X-Ray diffraction (XRD) technique. The XRD spectra do not contain any prominent peak, which confirms the amorphous nature of the samples. Results and Discussion Theoretical basis The study of the crystallisation process under non-isothermal conditions is generally based on Johnson-Mehl- Avrami (JMA) (M. Avrami, 1939-1940-1941) equation:    () 1 exp 1 n xt Kt    where x(t) is the volume fraction of the initial material transformed at time t, n is the Avrami exponent and K is the reaction rate constant which is related to the temperature as:  exp 2 0 E a K K kT         where K 0 is the frequency factor, E a denotes the activation energy for the crystallisation process, k is the Boltzmann constant and T is the isothermal temperature. One of the theoretical bases for interpreting the DSC results, especially for determining the activation energy, is Kissinger (H. E. Kissinger, 1957) method using the highest rate of the process at maximum peak: