Misfit dislocations in composites with nanowires

Abstract

A theoretical model is suggested which describes the generation and evolution of misfit dislocations in composite solids containing nanowires with rectangular cross-section. In the framework of the model, the ranges of the geometric parameters (nanowire sizes, misfit parameter, interspacing between the nanowire and the free surface of the composite) are calculated at which the generation of various misfit dislocation configurations (loops, semi-loops and dipoles) is energetically favourable. Transformations of these dislocation configurations and their specific features are discussed.

Equilibrium position of misfit dislocation dipole and critical parameters of buried strained nanoscale inhomogeneity in system of viscoelastic matrix

“…Following the work of GUTKIN et al [12] , the generation of the MD dipole is allowed if the total-energy variation is calculated from the inclusion and matrix configuration free of dislocations is negative d mˆŴ…”

“…Recently, the study of it has become very popular. The formation of misfit dislocations (MDs) parallel to axis of nanowires has been studied in triangular cross sections [5] , circular cross sections [6] , and rectangular cross sections [7] . The mechanism for the nucleation of dislocation dipoles at nanoparticles in nanocomposite solids is suggested by OVID'KO and SHEINERMAN [8] .…”

Equilibrium positions of misfit dislocations in a nanolayer embedded in a matrix

“…Likewise, the dislocation emission from nanovoid has been studied taking into account the effect of neighbouring nanovoids and surface stress, and a model of nanovoid growth has been proposed in ductile porous materials [20]. In the case of nanowires of rectangular cross-section embedded in composites, the effects of misfit strain, nanowire size or interspacing between the nanowires have been characterized on the introduction in the nanowire interfaces of loops, semi-loops and dipoles of dislocations [21]. For 2 A C C E P T E D M A N U S C R I P T spherical precipitates embedded in a matrix, the introduction of dislocations has been also considered [22,23,24,25,26].…”

Misfit stress relaxation in composite nanoparticles

“…For example, the misfit strain, which is a special type of residual strains caused by the difference in lattice parameters of crystals in contact, changes the energy gap in semiconductor nanoparticles (quantum dots) embedded in epitaxial layers (Andreev & O'Reilly, 2000;Bimberg, Grundmann, & Ledentsov, 1996;Peng et al, 2005), thus modifying the electronic and optical properties of light-emitting devices (injection lasers and light-emitting diodes) on quantum dots. On the other hand, the residual strains and stresses in CNPs can relax through generation of various defects, in particular, misfit dislocations as is the case with planar heteroepitaxial structures (Beanland, Dunstan, & Goodhew, 1996;Fitzgerald, 1991;Freund & Suresh, 2003;Gutkin, Kolesnikova, & Romanov, 1993;Jain, Willis, & Bullough, 1990;Jain, Harker, & Cowley, 1997;Matthews, 1979;Van der Merwe, 1991;Vdovin, 1999), nanoislands on substrates (Chen et al, 1996;Gatti, Marzegalli, Zinovyev, Montalenti, & Miglio, 2008;Liu, Ross, & Schwarz, 2000;Ovid'ko & Sheinerman, 2006;Wang et al, 2011;Zou, Liao, Cockayne, & Jiang, 2002), quantum dots Chaldyshev, Bert, Kolesnikova, & Romanov, 2009;Kolesnikova & Romanov, 2004a, 2004bKolesnikova, Romanov, & Chaldyshev, 2007;Ovid'ko & Sheinerman, 2006) and wires (Gosling & Willis, 1995;Gutkin, Ovid'ko, & Sheinerman, 2003;Ovid'ko & Sheinerman, 2006) in epitaxial layers, core-shell (Aifantis, Kolesnikova, & Romanov, 2007;Gutkin, Ovid'ko, & Sheinerman, 2000;Goldthorpe, Marshall, & McIntyre, 2008;Kavanagh, 2010;Sheinerman & Gutkin, 2001;Ovid'ko & Sheinerman, 2006…”