Title :
Thermal stability of CoFe, Co and NiFe/Co spin valves
Author :
Zeltser, Alexander M. ; Péntek, Katalin ; Menyhárd, Miklós ; Sulyok, Attila
Author_Institution :
Eastman Kodak Co., San Diego, CA, USA
fDate :
7/1/1998 12:00:00 AM
Abstract :
The magnetotransport and magnetic properties of three types of spin valves containing CoFe and Co in the free and pinned layers were investigated as a function of annealing temperature. The microchemical changes induced by annealing were correlated with the evolution of spin valve properties. Auger depth profiling and X-ray diffraction revealed that excellent thermal stability up to 220°C of the spin valves containing CoFe and Co can be attributed to an improvement in perfection of the as-sputtered, initially compositionally intermixed Co(Fe)/Cu/Co(Fe) and NiFe/Ta interfaces. The best overall thermal stability was exhibited by the 50Ta/20NiFe/30CoFe/23Cu/50CoFe/90FeMn/50Ta (layer thicknesses in Å) spin valve. After annealing for 2 hours at 260°C, it showed magnetoresistance ratio of 7.5%, exchange pinning field of 165 Oe, interlayer coupling field of ~11 Oe and easy axis coercivity of <4 Oe
Keywords :
Auger effect; annealing; cobalt; cobalt alloys; coercive force; giant magnetoresistance; iron alloys; magnetic heads; magnetic multilayers; nickel alloys; thermal stability; 220 degC; Auger depth profiling; NiFe-Co-Cu-Co-FeMn; NiFe-Co-Cu-Co-NiFe-FeMn; NiFe-CoFe-Cu-CoFe-FeMn; X-ray diffraction; annealing; easy axis coercivity; exchange pinning field; giant magnetoresistance; interlayer coupling field; microchemical changes; spin valves; thermal stability; Annealing; Coercive force; Giant magnetoresistance; Magnetic field measurement; Magnetic heads; Magnetic properties; Spin valves; Temperature; Thermal stability; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
