title: Strain Concentration at the Boundaries in 5-Fold Twins of Diamond and Silicon.
abstract: Widely found in metals, semiconductors, oxides, and even organic materials, multiple twinning has important implications in engineering applications of materials. In this work, the intrinsic strain in 5-fold twins of diamond and silicon has been studied combining aberration-corrected electron microscopy and first-principles calculations. In contrast to metallic 5-fold twins, where the strain distribution is relatively smooth, the semiconductor systems show significant strain concentration at the twin boundaries, which is shear modulus dependent. In silicon with moderate strain concentration, the electronic frontier orbitals are located at the center of the 5-fold twins. Accompanying the increased strain concentration in diamond, however, the frontier orbitals are pushed to the surface. The modification of strain state and surface electronic structure by materials elasticity suggest possible routes to tune catalytic, electronic, and mechanical properties of materials.
authors.affiliation: National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China and State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Rong
authors.identifier: http://orcid.org/0000-0003-1687-3597
authors.initials: R
authors.lastname: Yu
authors.affiliation: National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China and State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Mechanical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Jia Dao
authors.initials: JD
authors.lastname: Wang
authors.affiliation: National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China and State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
keywords: 5-fold twins; brittleness; diamond; elasticity; frontier orbital; silicon; strain concentration; twin boundary