Thickness dependence of parallel and perpendicular anisotropic resistivity in Ta/NiFe/IrMn/Ta multilayer studied by anisotropic magnetoresistance and planar Hall effect

Abstract

Ferromagnetic layer thickness dependence of anisotropic magnetoresistivities in Ta/NiFe(t)/IrMn (10 nm)/Ta has been investigated for t=3, 4, 5, 7, 8, 10, 12, 15, and 20 nm by the method of anisotropic magnetoresistance and planar Hall effect. Our results revealed that the parallel and perpendicular resistivity components performed a varying function with increment in NiFe thickness. Both the resistivities at first were observed to increase when the NiFe thickness increases from 3 to 10 nm; then for the NiFe thicknesses from 10 to 20 nm, the resistivities of NiFe layer decrease as the NiFe thickness increases. However, the anisotropic resistivity change, which is the difference between parallel and perpendicular resistivities, was observed to increase for the whole range of thicknesses when the NiFe thickness increases. The measured quantities were found to be in good agreement with the theoretically estimated parameters using single domain model; thus these behaviors are well explained based on the modern electron theory transition metals. (c) 2007 American Institute of Physics.