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arXiv · 1204.2154

Crystal structure of Cu-Sn-In alloys around the η phase field studied by neutron diffraction

Gabriela Aurelio·Silvana A Sommadossi·Gabriel J Cuello
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Abstract

The study of the Cu-Sn-In ternary system has become of great importance in recent years, due to new environmental regulations forcing to eliminate the use of Pb in bonding technologies for electronic devices. A key relevant issue concerns the intermetallic phases which grow in the bonding zone and are determining in their quality and performance. In this work, we focus in the η-phase (Cu2In or Cu6Sn5) that exists in both end binaries and as a ternary phase. We present a neutron diffraction study of the constitution and crystallography of a series of alloys around the 60 at.% Cu composition, and with In contents ranging from 0 to 25 at.%, quenched from 300\degreeC. The alloys were characterized by scanning electron microscopy, probe microanalysis and high-resolution neutron diffraction. The Rietveld refinement of neutron diffraction data allowed to improve the currently available model for site occupancies in the hexagonal η-phase in the binary Cu-Sn as well as in ternary alloys. For the first time, structural data is reported in the ternary Cu-Sn-In η-phase as a function of composition, information that is of fundamental technological importance as well as valuable input data for ongoing modelisations of the ternary phase diagram.

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Gabriela Aurelio, Silvana A Sommadossi, Gabriel J Cuello. 2012-04-10. Crystal structure of Cu-Sn-In alloys around the η phase field studied by neutron diffraction. https://doi.org/10.1007/s11664-012-2193-4

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