Estudo termodinâmico de gelos de spin em uma geometria do tipo malha

• Autor(a) principal: Gobbi, Robson Santos
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4273
• topic: Termodinâmica; Materiais nanoestruturados; Física do estado sólido; Monte Carlo, Método de; Nanomagnetismo; Thermodynamics; Nanostructured materials; Solid state physics; Monte Carlo method; Nanomagnetism; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA

This dissertation is the study of materials called spin ice, the among several properties they exhibit magnetic excitations that behave like magnetic monopoles. However, these monopolesalways come in pairs and having a binding energy (string) between them that prevents their division. In this paper we proposed a new geometry in order to examine the possibility of separation of such pairs, this geometry is built on the basis of increasing frustration among the entities of the system. We also studied the thermodynamic properties of the system as well as energy, magnetization, magnetic susceptibility and specific heat. These quantities were calculated for different network sizes and under two boundary conditions, one open and one closed. For the calculation of these quantities the Monte Carlo methods (Metropolis algorithm) and Sum of Ewald were used. Some of the results obtained were the emergence of vortex as ground state of the system with open boundary conditions, the dependence of the energy of the ground state with the network size and distinction between phases, one ordered and one disordered.