Navegando por Autor "Dorneles, Lúcio S."
Agora exibindo 1 - 2 de 2
- Resultados por página
- Opções de Ordenação
Artigo Exchange-biased SiO2/Co/CoO granular multilayers deposited by sequential sputtering(Elsevier, 2017-10-01) Gomes, Matheus Gamino; Michea, Sebastián; Denardin, Juliano C.; Schelp, Luiz F.; Corrêa, Marcio Assolin; Bohn, Felipe; Dorneles, Lúcio S.We investigate the magnetic properties in a system engineered to present Co grains laterally surrounded by a CoO matrix. By considering ferromagnetic SiO2/Co/CoO granular multilayers produced by sequential sputtering deposition, we verify that the Co grains present strong interfacial exchange coupling with the CoO matrix, assigned by the exchange bias effect as well as the raise of the Co blocking temperature. Morever, through magnetization and Hall resistivity experiments, we observe that the antiferromagnetic ordering temperature and exchange bias are dependent on the thickness of the antiferromagnetic material, attributed to finite size effects, as well as we find that the Co blocking temperature is raised as the CoO layer becomes thicker. We discuss the experimental results in terms of the growth mode of the layers, morphological properties of the multilayers, and temperature dependence of the magnetic behavior. The results place the sequential sputtering deposition as a promising alternative technique to produce Co/CoO granular multilayersArtigo Handling magnetic anisotropy and magnetoimpedance effect in flexible multilayers under external stress(Elsevier, 2016-12-15) Agra, Kennedy Leite; Bohn, Felipe; Mori, T. J. A.; Callegari, Gustavo Luiz; Dorneles, Lúcio S.; Corrêa, Marcio AssolinWe investigate the dynamic magnetic response though magnetoimpedance effect of ferromagnetic flexible NiFe/Ta and FeCuNbSiB/Ta multilayers under external stress. We explore the possibility of handling magnetic anisotropy, and consequently the magnetoimpedance effect, of magnetostrictive multilayers deposited onto flexible substrates. We quantify the sensitivity of the multilayers under external stress by calculating the ratio between impedance variations and external stress changes, and show that considerable values can be reached by tuning the magnetic field, frequency, magnetostriction constant, and external stress. The results extend possibilities of application of magnetostrictive multilayers deposited onto flexible substrates when under external stress and place them as very attractive candidates as element sensor for the development of sensitive smart touch sensors