My publicationsThis is a collection of my refereed scientific publications.
Note that all publications are copyright to some publishing company; you are not allowed to republish any part of this material in any context without permission from the publisher.
Papers submitted to or published in Physical Review are subject to the following copyright notice:
"Copyright The American Physical Society 19XX. All rights reserved. Except as provided under U. S. copyright law, this work may not be reproduced, resold, distributed or modified without the express permission of The American Physical Society."
List of publications with abstracts
We use molecular dynamics
computer simulations to study the damage production by collision
cascades at Si/Ge and AlAs/GaAs and InAs/GaAs interfaces.
For the arsenide systems we find that present interatomic
potentials have troubles in describing even the basic elastic
and melting properties.
We report parameter refinements which give a significantly
better description of these properties.
Our results for collision cascades at strained semiconductor
interfaces show a strong asymmetry in the distribution of
vacancies and impurities produced at the interface.
The effect is explained as a strain-induced effect
analogous to the classical Kirkendall effect.
We also show that although the chemical composition
of compound semiconductors does not strongly affect the overall
evolution of collision cascades, the composition
may in some cases have a significant effect on
the final distribution of defects.
Comput. Mater. Sci. 18 (2000)
It has recently become clear that electron irradiation can recrystallise
amorphous zones in semiconductors even at very low temperatures, and even
when the electron beam energy is so low that it can not induce atomic
displacements by ballistic collisions. We study the mechanism of this
effect using classical molecular dynamics augmented with models describing
the breaking of covalent bonds induced by electronic excitations.
We show that the bond-breaking allows geometric rearrangement at the
crystal-amorphous interface which can induce recrystallisation in silicon
without any thermal activation.
Phys. Rev. B 64, 125313 (2001)
Recent developments in thin film manufacturing have
given rise to an interest in the growth of nanocrystalline films on
one hand, and using cluster deposition to grow epitaxial films on
the other hand. Both kinds of films can be grown using cluster
deposition at soft landing conditions. But for both kinds of growth
one has to know the maximum cluster size for which a cluster becomes
fully epitaxial with the substrate. Using molecular dynamics computer
simulations we determine this cluster size limit for landing
on a smooth surface in the temperature
range 0-750 K. Below the limit completely epitaxial growth is
possible, and above it a nanocrystalline phase will form.
Thin Solid Films 425/1-2, 297-303 (2003)
Using classical molecular dynamics method we have studied the burrowing mechanism of Co nanoclusters on a Cu substrate. We found that
there are primarily two different mechanisms for the burrowing, depending on the configuration of the cluster after thermal deposition. Deposited
clusters with an epitaxial configuration will burrow through vacancy migration along the Co-Cu interface, and non-aligned clusters
burrow through disordered motion of atoms. The re-alignment of the non-aligned clusters was found to be due to a collective rotational
movement of the whole cluster during the burrowing process. We discuss these results and perform a comparison with experimental
and previously simulated results.
Phys. Rev. B 67, 075415 (2003)
We have examined the burrowing of Co nanoclusters deposited on a Cu surface with classical molecular dynamics simulations. Our simulations show that two
different mechanisms of burrowing are dominating depending on the orientation of the deposited nanocluster. The burrowing mechanism for epitaxial
nanoclusters was found to be vacancy migration along the Co-Cu interface and for non-aligned nanoclusters the mechanism is disordered motion of atoms along
the Co-Cu interface. The re-alignment effect of the Co nanoclusters found in experiments was found to be due to a collective rotational movement of the whole
cluster during the burrowing process. We present our results and compare these to previous experimental and simulated results.
IBMM 2002 conference paper.
NIMB 206C, pp. 66-70 (2003)
Using molecular dynamics simulations combined with kinetic Monte Carlo methods we have studied the evolution of copper nanoclusters on a copper (100) surface.
We have developed a method for relaxing the clusters into a suitable configuration for input into the kinetic Monte Carlo method using molecular dynamics.
Using kinetic Monte Carlo methods we have simulated the evolution of clusters with sizes of 22-2045 atoms at temperatures of 220-1020 K.
We found that the Cu clusters on the surface will be reduced to one monolayer if given enough time to relax, and that this process shows an Arrhenius
behaviour.In this article we present the relaxation method we developed and our observations for the evolution of the clusters.
J. Phys.: Condens. Matter 16, 2995 - 3003 (2004)
Using classical molecular dynamics methods and rate equations we have studied
the effect of Co deposition on a Co island at a Ag(100) surface. In the molecular
dynamics simulations Co atoms were deposited on islands of sizes from 2 ×
2 to 6 × 6 atoms with an energy of 25 eV at an incident angle of 20 degrees
off normal. From the MD simulation results we determined the functional form of
the fragmentation kernel used in the rate equations as well as its parameters.
The MD results also showed that irradiation induced detachment from the island is
common, while dissociation events of the island are very rare. Studying the growth
process using rate equations, which included the restrictions deduced from the MD
results, gave us island size distributions which agree with experimentally measured
distributions. Thus our results show that the submonolayer growth process can be
explained solely by irradiation induced detachment from the island.
Phys. Rev. B 71, 075411 (2005)