Thickness dependence of exchange anisotropy in NiFe/IrMn bilayers studied by Planar Hall Effect

• Published in: Journal of magnetism and magnetic materials Vol. 305; no. 2; pp. 432 - 435
• Main Authors: Thanh, N.T., Chun, M.G., Ha, N.D., Kim, K.Y., Kim, C.O., Kim, C.G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2006; Elsevier Science
• Subjects: AMR; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Exchange biased-coupling; Magnetic properties and materials; Magnetic properties of nanostructures; Physics; Planar Hall Effect; Planar Hall Effect; Exchange biased-coupling; AMR; Effective field approximation; Electrical conductivity; Nickel alloys; Magnetic field effects; Iridium alloys; Hall effect; Iron alloys; Nanostructures; Thin films; Thickness; Anisotropy; Size effect; Manganese alloys; Exchange interactions; Bilayers; Transition element alloys
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2006.01.228

Planar Hall Effect (PHE) in NiFe( t)/IrMn(10.0 nm) thin film structures has been experimentally investigated as a function of NiFe thickness in the range from 3 to 20 nm, under the applied magnetic field perpendicular to the easy axis. The PHE voltage change and its field sensitivity increase with NiFe thickness, but the field interval of two voltage maxima decreases with the thickness. There are good agreements between measured and calculated PHE voltage profiles, where the parameters of exchange-biased and effective anisotropy fields have been characterized to decrease with NiFe thickness. However, an anisotropic resistivity change increases as the NiFe thickness increases. These analyses suggest that PHE is the effective method, inferred to single domain, to determine the electrical and magnetic parameters in magnetic devices.