Determination of fine magnetic structure of magnetic multilayer with quasi antiferromagnetic layer by using polarized neutron reflectivity analysis

We carried out polarized neutron reflectivity (PNR) analysis to determine the fine magnetic structure of magnetic multilayers with quasi-antiferromagnetic (quasi-AFM) layers realized by 90-deg coupling using two Co₉₀Fe₁₀ layers, and quantitatively evaluated the magnetization of quasi-AFM layers. Two types of samples with different buffer layers, Ru buffer and a NiFeCr buffer, were investigated and the average angles between the respective magnetization of the two Co₉₀Fe₁₀ layers were estimated to be +/- 39 degrees and +/- 53 degrees. In addition, less roughness was found in the NiFeCr buffer sample resulting stronger 90-deg coupling. A perfect quasi-AFM is expected to be realized by a flat interface of the magnetic multilayer.