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

Volume

33

Issue

5

fYear

1997

fDate

9/1/1997 12:00:00 AM

Firstpage

3984

Lastpage

3986

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-Ni₄₀Fe₁₀Co₅₀; 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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.619637

Filename

619637