Local Lattice Instability Analysis on Silicon by Tersoff Potential

• YASHIRO Kisaragi

  Graduate School of Eng., Kobe Univ.

• FUJIHARA Masahiro

  Student of Faculty of Eng., Dept. of Mech. Eng., Kobe Univ.

Bibliographic Information

Other Title

• Ｔｅｒｓｏｆｆポテンシャルによるシリコンの局所格子不安定性解析
• Tersoff ポテンシャル ニ ヨル シリコン ノ キョクショ ゴウシ フアンテイセイ カイセキ

Abstract

We have long discussed the onset mechanism of inelastic deformation of crystalline/amorphous metals based on atomic elastic stiffness or atomic stability. In the present study, we have first applied our “local lattice instability analysis” to silicon with Tersoff interatomic potential. For a comprehensive discussion including the effect of thermal fluctuation and structural inhomogeneity such as surface and grain boundaries, we have performed various tensile simulations against bulk/nanowire of Si single crystal, laminate-bulk/bamboo-nanowire with Σ5 twist grain boundary. Here, we have prepared different 8 set changing the random number for initial Maxwell-Boltzmann velocity distribution for each simulation. Not only the stress-strain response, but also the atomic elastic stiffness at each atom point, B^α_ij, is evaluated numerically by Δσ^α_i/Δε_j(Voigt notation) against local strain perturbation. The change in the average, standard deviation of det B^α_ij and the number of det B^α_ij < 0 atoms have brought us many significant insights, especially in e.g. (1) in the case of bulk single crystal under T = 1K, we have found a slight and smooth stress peak before the unstable stress drop, (2) the standard deviation of det B^α_ij began to increase at the peak of (1) and then the average of det B^α_ij became negative or reached “global instability” at the stress drop, (3) even in the systems with thermal fluctuation and structural inhomogeneity, the standard deviation of det B^α_ij decreases at the initial stage of tension, but it increase again when the lower bound of the standard deviation reaches zero well before the unstable stress drop.

Journal

• Journal of the Society of Materials Science, Japan

  Journal of the Society of Materials Science, Japan 60 (11), 968-975, 2011

  The Society of Materials Science, Japan

Keywords

• Dynamics simulation
• Local lattice instability analysis
• Silicon
• Tersoff potential
• Surface
• Σ5 Twist grain boundary

Details

• CRID: 1390001205444431744
• NII Article ID: 130001396963
• NII Book ID: AN00096175
• DOI: 10.2472/jsms.60.968
• ISSN: 18807488
• ISSN: 05145163
• NDL BIB ID: 023339944
• Web Site: http://id.ndl.go.jp/bib/023339944
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I023339944
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed