Orientation-dependent transport properties of Cu3Sn. (1st April 2022)

• Record Type: Journal Article
• Authors: Daeumer, Matthias; Sandoval, Ernesto D.; Azizi, Arad; Bagheri, Morteza H.; Bae, In-Tae; Panta, Sitaram; Koulakova, Ekaterina A.; Cotts, Eric; Arvin, Charles L.; Kolmogorov, Aleksey N.; Schiffres, Scott N.
• Is Part Of: Acta materialia. Volume 227(2022)
• Publication Date: 2022-04-01
• Subjects: Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2022.117671
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Cu3 Sn, a well-known intermetallic compound with a high melting temperature and thermal stability, has found numerous applications in microelectronics, 3D printing, and catalysis. However, the relationship between the material's thermal conductivity anisotropy and its complex anti-phase boundary superstructure is not well understood. Here, frequency domain thermoreflectance was used to map the thermal conductivity variation across the surface of arc-melted polycrystalline Cu3 Sn. Complementary electron backscatter diffraction and transmission electron microscopy revealed the thermal conductivity in the principal a, b, and c orientations to be 57.6, 58.9, and 67.2 W/m-K, respectively. Density functional theory calculations for several Cu3 Sn superstructures helped examine thermodynamic stability factors and evaluate the direction-resolved electron transport properties in the relaxation time approximation. The analysis of computed temperature- and composition-dependent free energies suggests metastability of the known long-period Cu3 Sn superstructures while the transport calculations indicate a small directional variation in the thermal conductivity. The ∼15% anisotropy measured and computed in this study is well below previously reported experimental values for samples grown by liquid-phase electroepitaxy. Graphical abstract: Image, graphical abstract