Title :
Enhanced spin-valve giant magneto-resistance in non-exchange biased sandwich films
Author :
Mao, M. ; Cerjan, C. ; Law, B. ; Grabner, F. ; Miloslavsky, L. ; Chien, C.
Author_Institution :
Lawrence Livermore Nat. Lab., CA, USA
fDate :
9/1/2000 12:00:00 AM
Abstract :
A large giant magnetoresistance (GMR) value of 7.5% has been measured in simple NiFeCo(1)/Cu/NiFeCo(2) sandwich films grown on a 30 Å Cr seed layer. This spin-valve GMR effect is consistent with the differential switching of the two NiFeCo layers due to an enhanced coercivity of the NiFeCo(1) layer grown on the Cr seed layer. A change in growth texture of the NiFeCo(l) layer from fcc (111) to bcc (110) crystallographic orientation leads to an increase in magnetic anisotropy and an enhancement in coercivity. The GMR value increases to 8.7% when a thin CoFe interfacial enhancing layer is incorporated. Further enhancement in GMR values up to 14% is seen in the sandwich films by nano-oxide layer formation. The specular reflection at the oxide/magnetic layer interface further extends the mean free path of spin-polarized electrons
Keywords :
cobalt alloys; coercive force; copper; ferromagnetic materials; giant magnetoresistance; iron alloys; magnetic anisotropy; magnetic multilayers; nickel alloys; spin valves; NiFeCo-Cu-NiFeCo; coercivity; crystallographic orientation; differential switching; enhanced spin-valve giant magnetoresistance; growth texture; magnetic anisotropy; mean free path; nano-oxide layer formation; nonexchange biased sandwich films; oxide/magnetic layer interface; specular reflection; spin-polarized electrons; Chromium; Coercive force; Crystallography; Electrons; Giant magnetoresistance; Magnetic anisotropy; Magnetic films; Optical films; Perpendicular magnetic anisotropy; Reflection;
Journal_Title :
Magnetics, IEEE Transactions on
