Spin-transfer devices utilize both the charge and spin nature of electron transport and show great promise for highly compact magnetic memory. The degree to which spin-polarized transport can proceed, characterized by magnetic Gilbert damping, is strongly dependent on the thickness of the ferromagnetic layer(s) involved. However, without detailed knowledge of the ferromagnetic structure it is very difficult to distinguish between magnetic damping related to interface effects and to intrinsic magnetocrystalline anisotropy changes.

As layered systems become ultra-thin, x-ray diffraction becomes more challenging due to Debye broadening and to the often polycrystalline nature of ultra-thin films. Additionally, ultra-thin layers can acquire both induced strain and produce significant interlayer interference not normally observed in thicker samples. The combination of these effects can cause the Bragg peaks of two distinct, but closely lattice matched layers to significantly overlap. Motivated by the need for a general, minimal assumption method to handle such situations, multi-energy, element sensitive anomalous diffraction has been developed. It was successfully applied to solve the structure and trigonal strain of single cobalt layers 12 to 65 Å thick buried within a Pt|Cu|Co|Cu|Pt structure. The method is sensitive to texture and lattice spacing of ± 0.01 Å. The anomalous results are compared with extended x-ray absorption fine structure (EXAFS) measurements.

Magnetic orbital and spin moments examined with x-ray magnetic circular dichroism (XMCD) are correlated with the strain induced structural distortion measured. In Co ultra-thin films the trigonal strain appears to be responsible for the increased orbital to spin moment ratio observed far a range of ultra-thin film thicknesses. In t Co|2t Ni multilayers the strain is great enough to potentially negate the perpendicular magnetic anisotropy associated with the enhancement of Co to Ni interface in ultrathin layers with t = 4 Å or less. In both cases combining detailed structural characterization with magnetic spectroscopy proves to be a powerful approach in understanding the origin of magnetic behavior.