Minimum energy path for the nucleation of misfit d... - BV FAPESP
Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Minimum energy path for the nucleation of misfit dislocations in Ge/Si(001) heteroepitaxy

Full text
Author(s):
Trushin, O. [1] ; Maras, E. [2, 3] ; Stukowski, A. [4] ; Granato, E. [5, 6] ; Ying, S. C. [6] ; Jonsson, H. [2, 7] ; Ala-Nissila, T. [2, 3, 6]
Total Authors: 7
Affiliation:
[1] Russian Acad Sci, Yaroslavl Branch, Inst Phys & Technol, Yaroslavl 150007 - Russia
[2] Aalto Univ, Sch Sci, Dept Appl Phys, FIN-00076 Espoo - Finland
[3] Aalto Univ, Sch Sci, COMP Ctr Excellence, FIN-00076 Espoo - Finland
[4] Tech Univ Darmstadt, Inst Mat Wissensch, D-64287 Darmstadt - Germany
[5] Inst Natl Pesquisas Espaciais, Lab Associado Sensores & Mat, BR-12227010 Sao Jose Dos Campos, SP - Brazil
[6] Brown Univ, Dept Phys, Box 1843, Providence, RI 02912 - USA
[7] Univ Iceland, Fac Phys Sci, IS-107 Reykjavik - Iceland
Total Affiliations: 7
Document type: Journal article
Source: MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING; v. 24, n. 3 MAR 2016.
Web of Science Citations: 1
Abstract

A possible mechanism for the formation of a 90 degrees misfit dislocation at the Ge/Si(0 0 1) interface through homogeneous nucleation is identified from atomic scale calculations where a minimum energy path connecting the coherent epitaxial state and a final state with a 90 degrees misfit dislocation is found using the nudged elastic band method. The initial path is generated using a repulsive bias activation procedure in a model system including 75 000 atoms. The energy along the path exhibits two maxima in the energy. The first maximum occurs as a 60 degrees dislocation nucleates. The intermediate minimum corresponds to an extended 60 degrees dislocation. The subsequent energy maximum occurs as a second 60 degrees dislocation nucleates in a complementary, mirror glide plane, simultaneously starting from the surface and from the first 60 degrees dislocation. The activation energy of the nucleation of the second dislocation is 30% lower than that of the first one showing that the formation of the second 60 degrees dislocation is aided by the presence of the first one. The simulations represent a step towards unraveling the formation mechanism of 90 degrees dislocations, an important issue in the design of growth procedures for strain released Ge overlayers on Si(1 0 0) surfaces, and more generally illustrate an approach that can be used to gain insight into the mechanism of complex nucleation paths of extended defects in solids. (AU)

FAPESP's process: 14/15372-3 - Dynamics and topological defects in periodic media
Grantee:Enzo Granato
Support Opportunities: Regular Research Grants