A energia de Casimir e a energia de transição de fase Ferromagnética em Duplas Perovskquitas

This thesis is based on Bordag’s theory of Casimir energy. This proposal relates the Casimir energy between conductor plasma planes and the thermal energy in the transition in double ferromagnetic conductive perovskites. Using this association it was possible to calculate the critical temperature of...

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Detalles Bibliográficos
Autor: Rocha, Jefferson Rodrigues
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2017
País:Brasil
Institución:Universidade Federal do Espírito Santo (UFES)
Repositorio:Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
Idioma:portugués
OAI Identifier:oai:repositorio.ufes.br:10/7382
Acceso en línea:http://repositorio.ufes.br/handle/10/7382
Access Level:acceso abierto
Palabra clave:Superconductivity
Plasma conductors
Casimir Energy
Energia Casimir
Supercondutividade
Plasma condutores
Física
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Descripción
Sumario:This thesis is based on Bordag’s theory of Casimir energy. This proposal relates the Casimir energy between conductor plasma planes and the thermal energy in the transition in double ferromagnetic conductive perovskites. Using this association it was possible to calculate the critical temperature of Curie ???? relating the fraction of the energy between these materials and the parameters of Sommerfeld ?? of each compound. To evaluate experimentally our proposal we considered the transition temperatures ???? and the parameters of 3 samples: ????2??????????6,????2?? ????????6 e ????2?? ????????6.We have found that for these samples the distance ?? between the conducting planes is associated with the Curie temperature Tc. Our proposal for the calculation of ???? is consistent with the values found in the literature for samples with these characteristics (ferrometal and conductive). Based on our theory we proposed the preparation of a new sample that presented a parameter ?? similar to that of the sample ????2??????????6 thus generating a Curie temperature ???? ˜ 635??,namely:????1.8??0.2??????????6. This new compound is a double perovskite with ferromagnetic metallic characteristics and octahedral geometry formed by planes containing ??????6 and presenting ?? ?? = 635??.