doctoralThesis
Estudo da dinâmica da magnetização em multicamadas magnetostrictivas
Fecha
2015-09-10Registro en:
AGRA, Kennedy Leite. Estudo da dinâmica da magnetização em multicamadas magnetostrictivas. 2015. 120f. Tese (Doutorado em Física) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2015.
Autor
Agra, Kennedy Leite
Resumen
Magnetic multilayers have a considerable importance in the development of sensor elements
based on magnetoimpedância effect (MI). The advent of devices, using organic flexible substrate
have opened new frontiers for development of technology in several areas. Therefore it is
necessary the production and study of the magnetic and mechanical properties in ferromagnetic
films grown on flexible substrate. In this work, were produced ferromagnetic multilayer Py, Co
and FeCuNbSiB in flexible and rigid substrates, using the magnetron sputtering technique. In
the occasion, was used a methodology for characterizing the structural, mechanical and magnetic
properties. For this, the following measuring instruments were used: X-ray diffractometer,
vibrating sample magnetometer, impedance analyzer, dimensional measuring instruments and
finite element software. Through a meticulous analysis, we observed and correlate the MI effect
behavior, with the magnetic quasi-static, structural and mechanical properties. Observing
a strong dependence of MI with magnetostrictive saturation, when magnetoelásticas anisotropy
introduced by mechanical stresses. The magnetic properties of the ferromagnetic multilayers
of Py shown to be insensitive to mechanical stresses applied. Already, the ferromagnetic multilayers
Co, it was mainly a result, an increase in dispersion of MI linked to the increase in
mechanical stress. In the case, of the ferromagnetic multilayers of FeCuNbSiB, the inversion of
the anisotropy axis it is the most interesting result, by causing changes in the MI effect, bringing
very rich information on the dynamics of magnetization when mechanical stresses are applied
to the system.