Numéro |
J. Phys. III France
Volume 7, Numéro 12, December 1997
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Page(s) | 2325 - 2338 | |
DOI | https://doi.org/10.1051/jp3:1997262 |
J. Phys. III France 7 (1997) 2325-2338
TEM Imaging of Dislocation Kinks, their Motion and Pinning
J.C.H. Spence1, H.R. Kolar1 and H. Alexander21 Department of Physics and SEM, Arizona State University, Tempe, AZ. 85287, U.S.A.
2 Universit$\ddot{\rm a}$t zu Köln, Abteilung f$\ddot{\rm u}$r Metallphysik im II Physikalishen Institut, Zülpicher Str. 77, 50937, Köln, Germany
(Received 3 October 1996, revised 10 June 1997, accepted 21 August 1997)
Abstract
HREM lattice images have been obtained using "forbidden" reflections generated by (111) stacking faults in silicon lying normal
to the beam at temperatures up to 600
C. Stationary and video images of 30
/90
partial dislocations relaxing toward equilibrium are studied. The lattice images formed from these forbidden reflections
show directional fluctuations which are believed to be kinks, since, as expected from mobility measurements, a higher density
is observed on 90
partials than on 30
partials, whereas artifacts contribute equally. Video difference images are used to obtain direct estimates of kink velocity.
Observations of kink delay at obstacles, thought to be oxygen atoms at the dislocation core, yield unpinning energies and
the parameters of the obstacle theory of kink motion. The kink formation energy is obtained from the distribution of kink
pair separations in low-dose images. The kink migration rather than formation energy barrier is thus found to control the
velocity of unobstructed dislocations in silicon under these experimental conditions.
© Les Editions de Physique 1997