Estudo de Primeiros Princípios de Peapods de Carbono sob Pressão Hidrostática

• Ano de defesa: 2010
• Autor(a) principal: Paurá, Edson Nunes Costa
• Orientador(a): GUERINI, Silvete Coradi
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Maranhão
• Programa de Pós-Graduação: PROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICA/CCET
• Departamento: FISICA
• País: BR
• Palavras-chave em Português: Pressão Hidrostática; Bundles de Peapods de Carbono; Primeiros Princípios; Propriedades Estruturais; Propriedades Energéticas
• Palavras-chave em Inglês: Hydrostatic Pressure; Carbon Peapods; First Principle Calculation; Structural Properties
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: http://tedebc.ufma.br:8080/jspui/handle/tede/719

In this work the structural and energetic properties of C60@(17,0) carbon peapods bundle were studied under hydrostatic pressure. To study such properties we use ab initio quantum calculations based on the density functional theory in the approach of the generalized gradient approximation. All simulations were performed using the SIESTA code. The results indicate that the bundles in the study present two phase transitions, the first transitions occurring in range 2.0 GPa - 3.0 GPa and the second occurring around 15.0 GPa, in good agreement with the literature. The analysis of electronics properties through energy bands indicates that the ( it Peapods) from P < 3.0 GPa are semiconductor with visible reduction in the energy gap, while above 3.0 GPa the systems become metallic. Also the energy levels of the band are changed according to the hydrostatic pressure is being applied, such as breaking the degeneracy of the levels of valence bands and conduction bands. To each interval of pressure applied we also calculated the relative volume percentual and cohesive energy as a function of pressure.