Title :
Spin-valves with antiferromagnetic α-Fe2O3 layers
Author :
Hasegawa, N. ; Makino, A. ; Koike, F. ; Ikarashi, K.
Author_Institution :
Nagaoka Branch, Alps Electr. Co. Ltd., Tokyo, Japan
fDate :
9/1/1996 12:00:00 AM
Abstract :
We report that the spin-valve films using the antiferromagnetic α-Fe2O3 layers show good MR response due to the coercivity difference in an as-deposited state and due to the unidirectional biasing field after magnetic annealing. Both the high coercivity and the biasing field of the pinned layer is caused by an exchange coupling. The obtained MR ratio of 6.1% is higher than those of the other spin-valves using Fe-Mn or Ni-Mn owing to the high resistivity of the α-Fe2O3. Further higher MR ratio of 10% is achieved by imposing 1 nm-thick Co layers at the Ni-Fe/Cu interfaces. It was found that the free layer coercivity of these spin-valves is smaller than that in the Co-Pt/Cu/Ni-Fe sandwiches having the similar high coercivity of the pinned layer. High thermal stability and corrosion resistance were also confirmed in the α-Fe2 O3 spin-valves
Keywords :
antiferromagnetic materials; coercive force; copper; corrosion; exchange interactions (electron); ferromagnetic materials; iron alloys; iron compounds; magnetic annealing; magnetic multilayers; magnetoresistance; magnetoresistive devices; nickel alloys; thermal stability; 1 nm; Co layers; Co-Pt/Cu/Ni-Fe sandwiches; Fe-Mn; Fe2O3-Ni80Fe20-Cu-Ni 80Fe20-Cu; Ni-Fe/Cu interface; Ni-Mn; antiferromagnetic α-Fe2O3 layers; coercivity difference; corrosion resistance; exchange coupling; free layer coercivity; high resistivity; magnetic annealing; pinned layer; spin-valve films; thermal stability; unidirectional biasing field; Anisotropic magnetoresistance; Antiferromagnetic materials; Coercive force; Conductivity; Magnetic anisotropy; Magnetization; Perpendicular magnetic anisotropy; Sputtering; Thermal resistance; Thermal stability;
Journal_Title :
Magnetics, IEEE Transactions on
