Microstructural properties and peritectic reactions in a binary Co–Sn alloy by means of scanning electron microscopy and atom probe tomography

Khushaim, Muna; Alahmari, Fatimah; Kattan, Nessrin; Chassaing, Delphine; Boll, Torben

Abstract:
Recent studies of lithium-ion batteries suggest that the use of binary CoSn alloys as anodes should provide an improvement over currently used anode materials. However, the implementation of CoSn alloys is challenging due to uncertainties regarding the phase transformations within this system. In order to understand these, we evaluate the compositions of different intermetallic compounds produced via the peritectic reactions, nucleate and grow within the microstructure of binary Sn − 25 at.% Co by employing atom probe tomography (APT). The stoichiometric ${\rm{CoSn}}$ phase, which is produced upon the cooling of the melt, is not only found as part of the peritectic solidification sequence but also as clusters within the pure Sn phase. The ${{\rm{CoSn}}}_{2}$ phase was found as a nano sized layer and is attributed to the peritectic reaction between the ${\rm{CoSn}}$ phase and the pure Sn phase. The production of the ${{\rm{CoSn}}}_{3}$ compound was enhanced by the phase transformation of the ${{\rm{CoSn}}}_{2}$ phase. Furthermore, ${{\rm{CoSn}}}_{3}$ clusters had formed in the pure Sn phase. A limited solubility within the pure Sn phase was also determined to be (0.6 ± 0.1) at.% Co.

 Zugehörige Institution(en) am KIT Institut für Angewandte Materialien - Werkstoffkunde (IAM-WK)Karlsruhe Nano Micro Facility (KNMF) Publikationstyp Zeitschriftenaufsatz Publikationsjahr 2020 Sprache Englisch Identifikator ISSN: 2053-1591 KITopen-ID: 1000124198 HGF-Programm 49.02.08 (POF III, LK 02) Atom probe tomography Erschienen in Materials Research Express Verlag IOP Publishing Band 7 Heft 8 Seiten Art.Nr. 086508 Vorab online veröffentlicht am 13.08.2020 Schlagwörter knmf proposalID 2017-018-019469 APT FIB Nachgewiesen in Web of ScienceDimensionsScopus
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