Abstract
dc:description.abstractSolid surfaces have been investigated by the lattice statics and molecular dynamics methods. Body centred and face centred cubic crystals at O K were studied by lattice statics- Bulk lattice spacings and potential energies were calculated and found to agree with the values obtained by other workers. the body centred cube was found to be unstable for Mie potentials, and a new tetragonal face centred structure was obtained, with a potential energy at a local minimum. The importance of the truncation range of a potential was considered, and especially the need to include third nearest neighbours for body centred cubes. The relaxation of solid surfaces was calculated, and surface potential energies computed for (100) and (110) surfaces of face centred and body centred cubic crystals. The minimum energy lattices were subjected to constant strains, and relaxations in orthogonal directions calculated, to give values of Poisson’s ratios. The surface Poisson’s ratio was defined, and values obtained for layer and cumulative surface Poisson’s ratios. A relationship between surface stress and superficial work was extended to incorporate surface Poisson’s ratios, and values obtained for the surface stress of inert gas crystals. A preliminary investigation was carried out into the modelling of isolated clusters of particles by molecular dynamics. Two clusters were created and allowed to coalesce. The problems of adequate graphical representation of the clusters, and particularly their surface, were noted. A set of three parameters was proposed, which would be used to monitor the overall and boundary shapes of two merging clusters, and the diffusion of particles from one cluster into the other.
Degree
thesis:*- Name dc:type.qualificationname
- PhD
- Level dc:type.qualificationlevel
- Doctoral
- Grantor dc:publisher.institution
- De Montfort University
- Year dc:date.issued
- 1986
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Williams, Margaret Patricia