Estudo da fusão de superfície da prata por dinâmica molecular

• Ano de defesa: 2008
• Autor(a) principal: Gonçalves, Luis Gustavo Vieira
• Orientador(a): Rino, José Pedro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Carlos
• Programa de Pós-Graduação: Programa de Pós-Graduação em Física - PPGF
• País: BR
• Palavras-chave em Português: Física; Dinâmica molecular; Superfícies (Física); Transição de fase
• Palavras-chave em Inglês: Surface melting; Interfaces; Anisotropy; Crystals; Molecular dynamics; Transition Metals; Phase transitions
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufscar.br/handle/20.500.14289/5004

A study about surface melting on silver using equilibrium molecular dynamics simulation is the proposal of this work. We applied the Embedded Atom Method as the many-body interaction potential to describe Ag properties. Simulations were done in the microcanonical ensemble, for the study of bulk properties, and in the canonical ensemble, for simulations of the solid with surfaces. As a preliminary result, we obtained the equilibrium melting point Tm equal 1264(12)K from solid-liquid coexistence configurations. Surfaces were simulated using repeated slabs separated by vacuum in the z direction, while keeping periodic boundary conditions in the remaining directions. Results showed that Ag[110] is the lone orientation that has surface melting. Ag[111] maintains its crystalline structure even after reaching Tm, while it could be overheated by 100K. Other properties like density of states, thermal expansion and surface relaxation were in good agreement with experimental data.