Theoretical study of the structural, cohesive, electronic and thermodynamic properties of Cu-Sb intermetallic compounds

C. DELUQUE TORO; S.B. RAMOS; A.F. GARCÍA ECHEVERRÍA; A.S. MOSQUERA POLO; A. FERNÁNDEZ GUILLERMET

San Carlos de Bariloche

Simposio; Simposio Latinoamericano de Física del Estado Sólido (SLAFES) XXIII; 2018

Centro Atómico Bariloche

The current search for alloys appropriate for lead-free soldering applications has motivated a long-standing effort to establish the relevant properties of the alloys formed by Cu, i.e., the usual contact material, with the binary systems which are intended to replace the classical Sn-Pb low-melting alloy. The main part of the studies in the last decades focused onthe alloys formed by Cu with a key candidate for such a replacement, viz., the In-Sn system. More recently, there has been a growing interest in the effect ofadopting other related binaries, in particular, the Sn-Sb system, upon thequality and reliability of the joints. Since these aspects depend upon theproperties of the intermetallic compounds (ICs) formed by Cu with Sn and Sb, it is necessary to characterize in detail the physical properties of these ICs. In this context, the present study focuses on the properties of the ICs formed by Cu with Sb. Specifically, this work deals with the following ICs, which occur in the Cu-Sb phase diagram: Cu2Sb tP6, Cu3Sb-cF16, Cu3Sb-oP8, Cu10Sb3-hP26, Cu11Sb3-oC28. Thestructural, thermodynamic and electronic properties of these ICs are established theoretically in the framework of the Density-Functional Theory(DFT), using the Projector Augmented Waves (PAW) method in the Generalized Gradient (GGA) and Local-Density (LDA) approximation. Once the ground-state properties were established, various quantities describing the thermal and equation-of-state behavior at finite temperatures were determined, viz., CP, CV, and the Debye temperature, the thermal expansion coefficient and the Grüneisen parameter.Trends in the variation of these properties are established, and a comparison with the behavior of the related Cu-In and Cu-Sn alloys, recently studied by the current authors [1] is reported.[1] S. Ramos de Debiaggi, C. Deluque Toro, G.F. Cabeza, A. Fernández Guillermet, Journal of Alloys and Compounds, 542 (2012) 280-292.