58 research outputs found
Structure, barriers and relaxation mechanisms of kinks in the 90-degree partial dislocation in silicon
Kink defects in the 90-degree partial dislocation in silicon are studied
using a linear-scaling density-matrix technique. The asymmetric core
reconstruction plays a crucial role, generating at least four distinct kink
species as well as soliton defects. The energies and migration barriers of
these entities are calculated and compared with experiment. As a result of
certain low-energy kinks, a peculiar alternation of the core reconstruction is
predicted. We find the solitons to be remarkably mobile even at very low
temperature, and propose that they mediate the kink relaxation dynamics.Comment: 4 pages in a two column gzipped postscript file (128 K), containing 3
figures and one table. Submitted to Phys. Rev. Let
Atomic structure of dislocation kinks in silicon
We investigate the physics of the core reconstruction and associated
structural excitations (reconstruction defects and kinks) of dislocations in
silicon, using a linear-scaling density-matrix technique. The two predominant
dislocations (the 90-degree and 30-degree partials) are examined, focusing for
the 90-degree case on the single-period core reconstruction. In both cases, we
observe strongly reconstructed bonds at the dislocation cores, as suggested in
previous studies. As a consequence, relatively low formation energies and high
migration barriers are generally associated with reconstructed
(dangling-bond-free) kinks. Complexes formed of a kink plus a reconstruction
defect are found to be strongly bound in the 30-degree partial, while the
opposite is true in the case of 90-degree partial, where such complexes are
found to be only marginally stable at zero temperature with very low
dissociation barriers. For the 30-degree partial, our calculated formation
energies and migration barriers of kinks are seen to compare favorably with
experiment. Our results for the kink energies on the 90-degree partial are
consistent with a recently proposed alternative double-period structure for the
core of this dislocation.Comment: 12 pages, two-column style with 8 postscript figures embedded. Uses
REVTEX and epsf macros. Also available at
http://www.physics.rutgers.edu/~dhv/preprints/index.html#rn_di
Targeted inhibition of the Shroom3–Rho kinase protein–protein interaction circumvents Nogo66 to promote axon outgrowth
Specific features in the generation and motion of dislocations in silicon single crystals doped with nitrogen
Specific features in the generation and motion of dislocations in heat-treated silicon wafers
Dynamic characteristics of solids in microvolumes: Modern principles, techniques, and results of investigation
Multistage Radiation-Stimulated Changes in the Microhardness of Silicon Single Crystals Exposed to Low-Intensity β Irradiation
Structure of complexes responsible for radiation-stimulated softening of silicon single crystals
Stepwise transition from elastic to elastoplastic deformation at the initial stage of nanoindentation
Reversible changes in the microhardness of silicon crystals under electron irradiation with low doses
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