Domain structure and magnetoresistance of NiFe/Au/Co/Au multilayers with perpendicular anisotropy

The magnetic properties of sputtered [Ni80Fe20(2 nm)/Au(t(Au))/Co(t(Co))/Au(t(Au))](15) multilayers with t(Au) = 1.5-3 nm and t(Co)=0.6-1.5 nm were investigated with magnetic force microscope. The Ni80Fe20 layers possessed in-plane magnetic anisotropy while the sandwiching of Co layers between An layers ensured their perpendicular anisotropy through the influence of surface anisotropy. It led to the formation of a maze configuration of stripe domains. The stripe domains period lambda strongly depends on t(Co) changing from 0.9 to 0.3 mu m when t(Co) changes from 0.6 to 0.8 nm. Period lambda increases with An layers thickness, too. The values of stray fields originating from Co layers which act on Ni80Fe20 layers, in the range of 100 kA/m, estimated from magnetoresistive dependencies are in qualitative agreement with those evaluated from the model of infinitely long stripe domains with domain widths taken from MFM measurements. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.