Title :
Domain observations on NiFeCo/Cu/NiFeCo-sandwiches for giant magnetoresistive sensors
Author :
McCord, Jeffery ; Hubert, Alex ; Kools, Jacques C S ; Ruigrok, Jaap J M
Author_Institution :
Inst. fur Werkstoffwissenschaften, Erlangen-Nurnberg Univ., Germany
fDate :
9/1/1997 12:00:00 AM
Abstract :
We prepared NiFeCo-Cu-NiFeCo GMR sensor structures with crossed anisotropy. The ferromagnetic layers are weakly coupled. The measured GMR ratio is about 1.2%-smaller than the ratio derived from measurements on similar spin-valve structures. To explain the poor performance we studied the domains in the coupled ferromagnetic layers by Kerr microscopy. The magnetization processes are strongly influenced by the remaining weak ferromagnetic coupling and the occurrence of compensated wall structures. These irregularities lead to reduced GMR ratios. Also the formation of 360°-walls can be observed
Keywords :
Kerr magneto-optical effect; cobalt alloys; copper; ferromagnetic materials; giant magnetoresistance; iron alloys; magnetic domain walls; magnetic multilayers; magnetic sensors; magnetoresistive devices; nickel alloys; 360°-walls; GMR ratio; Kerr microscopy; Ni40Fe10Co50-Cu-Ni40 Fe10Co50; NiFeCo-Cu-NiFeCo GMR sensor structures; NiFeCo/Cu/NiFeCo-sandwiches; compensated wall structures; crossed anisotropy; domains; giant magnetoresistive sensors; magnetization processes; spin-valve structures; weak ferromagnetic coupling; Anisotropic magnetoresistance; Current measurement; Electrical resistance measurement; Giant magnetoresistance; Magnetic anisotropy; Magnetic domains; Magnetic field measurement; Magnetic sensors; Magnetization processes; Perpendicular magnetic anisotropy;
Journal_Title :
Magnetics, IEEE Transactions on
