Title :
Angle sensor using spin valve with SAF structure
Author :
Wang, Dexin ; Brown, Jay ; Hazelton, Tim ; Daughton, Jim M.
Author_Institution :
NVE Corp., Eden Prairie, MN, USA
Abstract :
An angle sensor using spin valve materials was designed, fabricated and tested. The spin valve material, composed of a top-pinned synthetic antiferromagnet layer for better standoff fields and a composite free layer for low coercivity and high magnetoresistance, has a structure of Ta-NiFeCo-CoFe-Cu-CoFe-Ru-CoFe-CrMnPt. The spin valve film showed switching of the free layer with low coercivity (5 Oe) and a plateau of the high field region (up to 500 Oe) after annealing at 250°C for 1 hour. Two half-Wheatstone-bridges provide cosine and sine functions to uniquely determine angular positions between the angle sensor and a disc-shaped permanent magnet from 0 to 360 degrees at 2-6 mm airgap values.
Keywords :
angular measurement; annealing; antiferromagnetic materials; chromium alloys; cobalt alloys; coercive force; copper; iron alloys; magnetic multilayers; magnetic sensors; magnetoresistance; manganese alloys; nickel alloys; permanent magnets; platinum alloys; ruthenium; spin valves; tantalum; 1 hour; 250 degC; Ta-NiFeCo-CoFe-Cu-CoFe-Ru-CoFe-CrMnPt; angle sensor; angular positions; annealing; coercivity; composite free layer; cosine functions; free layer switching; half-Wheatstone-bridges; magnetoresistance; permanent magnet; sine functions; spin valve; standoff fields; top-pinned synthetic antiferromagnet layer; Annealing; Antiferromagnetic materials; Coercive force; Composite materials; Magnetic materials; Magnetic sensors; Magnetoresistance; Materials testing; Permanent magnets; Spin valves;
Conference_Titel :
Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International
Print_ISBN :
0-7803-9009-1
DOI :
10.1109/INTMAG.2005.1464057
