Magnetization processes in spin-valve meanders for sensor applications

Author

Schäfer, Rudolf ; Chumakov, Dmitry ; De Haas, Oliver ; Schultz, Ludwig ; Maass, Wolfram ; Barholz, Kai-Uwe ; Mattheis, Roland

Author_Institution

IFW-Dresden, Dresden, Germany

Volume

39

Issue

4

fYear

2003

fDate

7/1/2003 12:00:00 AM

Firstpage

2089

Lastpage

2097

Abstract

We used Kerr microscopy to investigate the magnetization processes of NiFeCo/Cu/Co/FeMn spin-valve meanders for magnetoresistive sensors and compared them to processes in related single films and bilayers. We observed irregular switching, characterized by the irreversible decay of blocked domains or by domain nucleation at 360° walls, in the related films and in the free layer of the spin-valve system. Both effects are connected with hysteresis. Edge-curling walls are responsible for rotational hysteresis in the giant magnetoresistance signal of the spin valves, occurring during field rotation in clockwise and counterclockwise directions. The U-turns of the meanders and their shape have no relevant influence on the magnetization behavior and hysteresis effects.

Keywords

cobalt; copper; giant magnetoresistance; iron alloys; magnetic domains; magnetic hysteresis; magnetic multilayers; magnetic sensors; magnetic switching; manganese alloys; nickel alloys; spin valves; GMR signal; Kerr microscopy; NiFe-Co-Cu-Co-FeMn; U-turns; blocked domains; domain nucleation; edge-curling walls; giant magnetoresistance signal; irregular switching; irreversible decay; magnetic multilayers; magnetization processes; magnetoresistive sensors; rotational hysteresis; sensor applications; spin-valve meanders; Clocks; Gas detectors; Giant magnetoresistance; Hysteresis; Magnetic force microscopy; Magnetic sensors; Magnetization processes; Sensor phenomena and characterization; Shape; Spin valves;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2003.812787

Filename

1211188