Estudo de exchange bias via magnetorresistência anisotrópica

• Ano de defesa: 2013
• Autor(a) principal: Rosa, Diego Saldanha da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; BR; Física; UFSM; Programa de Pós-Graduação em Física
• Palavras-chave em Português: Magnetorresistência anisotrópica; Anisotropia; Simulação; Anisotropic magnetoresistance; Exchange bias; Anisotropy; Simulation; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/9237

Anisotropic magnetoresistance (AMR) corresponds to the change of R in an ferromagnetic material with the angle between electric current and magnetization. Sensors using this effect are suited to detect both angular and linear displacements. In this work, structural, magnetic and electric characterization were performed in order to study the exchange interaction between antiferromagnetic IrMn and ferromagnetic NiFe, in a bilayer and a multilayer. Simulations of the AMR measurements were performed and showed good agreement with the experimental data. Different anisotropy field values were observed. The difference between the anisotropy field and the exchange field values is responsible for the different AMR data sets extracted from each sample. The model takes into account the, anisotropy (uniaxial), Zeeman, and exchange-bias (unidirectional) energies was used to explain the observed behavior.