Estudo de exchange bias via magnetorresistência anisotrópica

• Autor(a) principal: Rosa, Diego Saldanha da
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• Texto Completo: http://repositorio.ufsm.br/handle/1/9237
• topic: Magnetorresistência anisotrópica; Anisotropia; Simulação; Anisotropic magnetoresistance; Exchange bias; Anisotropy; Simulation; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA

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.