23 research outputs found
Multiple scattering and attenuation corrections in Deep Inelastic Neutron Scattering experiments
Multiple scattering and attenuation corrections in Deep Inelastic Neutron
Scattering experiments are analyzed. The theoretical basis is stated, and a
Monte Carlo procedure to perform the calculation is presented. The results are
compared with experimental data. The importance of the accuracy in the
description of the experimental parameters is tested, and the implications of
the present results on the data analysis procedures is examined.Comment: 19 pages, 8 figure
Electromigration-Induced Flow of Islands and Voids on the Cu(001) Surface
Electromigration-induced flow of islands and voids on the Cu(001) surface is
studied at the atomic scale. The basic drift mechanisms are identified using a
complete set of energy barriers for adatom hopping on the Cu(001) surface,
combined with kinetic Monte Carlo simulations. The energy barriers are
calculated by the embedded atom method, and parameterized using a simple model.
The dependence of the flow on the temperature, the size of the clusters, and
the strength of the applied field is obtained. For both islands and voids it is
found that edge diffusion is the dominant mass-transport mechanism. The rate
limiting steps are identified. For both islands and voids they involve
detachment of atoms from corners into the adjacent edge. The energy barriers
for these moves are found to be in good agreement with the activation energy
for island/void drift obtained from Arrhenius analysis of the simulation
results. The relevance of the results to other FCC(001) metal surfaces and
their experimental implications are discussed.Comment: 9 pages, 13 ps figure