Role of the nonmagnetic layer in determining the Landé g-factor in a spin-transfer system

The microscopic origin of the Landé g-factor in two ferromagnetic/nonmagnetic (FM/NM) bilayer systems-Co/Cu and Ni/Pd-has been investigated using x-ray magnetic circular dichroism, resonant magnetic reflectivity, and band calculations. The FM/NM bilayer represents the building block of any complete spin-transfer structure (FM1/NM/FM2). The valence electronic structure is profoundly altered over a finite length across the FM/NM interface. A considerable charge transfer takes place from the NM to the FM material. This results in an enhancement of the orbital-to-spin magnetic moment ratio in the FM layer and an induced magnetic polarization in the NM layer. Both effects turn out to be crucial for a correct understanding of the g-factor in spin-transfer systems.