Structural and chemical diagnosis of magnetic multilayers by RAFS and XRF techniques

Elemental distribution of Ni, Mn and Co at the NiMn/Co and Co/NiMn interfaces of ultra-thin NiMn/Co multilayers and that of Bi in the Cu/NiFe/Bi/FeMn/Cu multilayers have been investigated by X-ray reflection anomalous fine structure (RAFS) and X-ray fluorescence (XRF) methods. For the as-grown sample of the NiMn/Co multilayers, a chemical intermixing region with the chemical component varying gradually from Co to CoMn is observed at the Co/NiMn interface, but not at the NiMn/Co interface. After annealing at 250 °C for 3, 10 and 20 h respectively, this gradual chemical component variation also appears at the NiMn/Co interface. For the Cu/NiFe/Bi/FeMn/Cu multilayers, the depth distributions of the Bi atoms of the samples with different thicknesses of Bi layer are obtained. The results show that the diffuse ability of Bi is strongly dependent on the thickness of the Bi layer.