Thermochimica Acta 419 (2004) 295–297 Short communication Phase equilibria in the quasibinary GaSb–Pb system Dragan Manasijevi´ c a,∗ , Dragana Živkovi´ c a , Mira Coci´ c b , Dušan Janji´ c a , Živan Živkovi´ c a a Department of Metallurgy, Technical Faculty, University of Belgrade, Vojske Jugoslavije 12, 19210 Bor, Serbia and Montenegro b Copper Institute, Zeleni bulevar 35, 19210 Bor, Serbia and Montenegro Received 3 February 2004; received in revised form 30 March 2004; accepted 5 April 2004 Abstract The phase relationships of the quasibinary GaSb–Pb section of the ternary Ga–Sb–Pb system were studied by means of the X-ray diffraction (XRD) and optical microscopy. Phase reactions were determined using differential thermal analysis (DTA). Based on this results phase diagram of the GaSb–Pb section was constructed, which was compared with literature data. © 2004 Elsevier B.V. All rights reserved. Keywords: Ga–Sb–Pb system; Phase diagram; Thermal analysis; X-ray diffraction; Optical microscopy 1. Introduction The equilibrium phase diagrams are important tool in understanding the interfacial reactions since they indicate the equilibrium state that the materials would attain if they were left for a sufficient length of time at a given temper- ature. Because of that they present a starting point for any study of metal–semiconductor systems. In order to inves- tigate the phase relationships in one of these systems the ternary Ga–Sb–Pb system, the quasibinary GaSb–Pb section was chosen for the experimental investigation in this work. The equilibrium phase diagrams for the constitutive binary systems are well defined. Based on the numerous available literature data Ngai et al. assessed the Ga–Sb system [1]. The stoichiometric compound Ga–Sb is the only intermediate phase within the system that crystallizes in the cubic zinc blende structure and melts congruently at 711.7 ◦ C. On the Sb-rich side eutectic reaction occurs at 589.3 ◦ C; on the Ga side a degenerate eutectic reaction occurs at 29.7 ◦ C. The phase relationships in the Ga–Pb system were inves- tigated first by Puschin et al. [2], who reported a monotectic transformation at 317 ◦ C and 86.47 at.% Pb. No results concerning the compositions of the equilibrium phases of the miscibility gap were given in that study. Greenwood [3] ∗ Corresponding author. Tel.: +381-30-424-547; fax: +381-30-424-547. E-mail address: dmanasijevic@tf.bor.ac.yu (D. Manasijevi´ c). determined the limits of the solid solubility while Predel [4] investigated the Ga–Pb system in the liquid state by differential thermal analysis and defined the contour of the miscibility gap. Ansara and Ajersch [5] assessed the Ga–Pb system. Mathon et al. [6] also assessed this system using a computerized optimization procedure. Lead and antimony form a eutectic system with limited solid solubilities. On the Pb-rich side the liquidus has been well established by Blumenthal [7] and the solidus by Rhines and Pellini [8]. Obinata and Schmid [9] determined the solid solubility by X-ray diffraction. Although there are many phase diagram data available for the constitutive binary systems, there seems to be only one published data for ternary the Ga–Sb–Pb alloys. Baranov et al. [10] gave complete calculated liquidus projection and phase diagram of the GaSb–Pb section. In this work differential thermal analysis, X-ray diffrac- tion and optical microscopy results were used for the phase diagram determination of the GaSb–Pb system. 2. Experimental The samples were prepared from gallium (99.99%), an- timony (99.99%) and lead (99.99%). Calculated amounts of the pure elements were weighted (±0.05 mg) into quartz glass ampoules that were subsequently sealed un- der vacuum (10 -1 Pa). The samples were homogenized at 0040-6031/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.tca.2004.04.004