Self-organized Sr leads to solid state twinning in nano-scaled eutectic Si phase

Mihaela Albu, Anirban Pal, Christian Gspan, C. Picu, Ferdinand Hofer, Gerald Kothleitner

Research output: Contribution to journalArticle

Abstract

A new mechanism for twin nucleation in the eutectic Al-Si alloy with trace Sr impurities is proposed.Observations made by sub-angstrom resolution scanning transmission electron microscopy andX-ray probing proved the presence of <110> Sr columns located preferentially at twin boundaries.Density functional theory simulations indicate that Sr atoms bind in the Si lattice only along the<110> direction, with preferential positions at first and second nearest neighbors for interstitialand substitutional Sr, respectively. Density functional theory total energy calculations confirm thattwin nucleation at Sr columns is energetically favorable. Hence, twins may nucleate in Si precipitatesafter solidification, which provides a different perspective to the currently accepted mechanism whichsuggests twin formation during precipitate growth.
Original languageEnglish
Pages (from-to)31635/1-31635/7
Number of pages7
JournalScientific Reports
Volume6
DOIs
Publication statusPublished - 2016

ASJC Scopus subject areas

  • Materials Science(all)

Fields of Expertise

  • Advanced Materials Science

Treatment code (Nähere Zuordnung)

  • Basic - Fundamental (Grundlagenforschung)

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