Layer-resolved imaging of magnetic interlayer coupling by domain-wall stray fields

Layer-resolved magnetic domain images of epitaxially grown Co/Cu/Ni trilayers on Cu(001) have been studied, taken by photoelectron emission microscopy using x-ray magnetic circular dichroism as a magnetic contrast mechanism. In these trilayers the Ni layers are magnetized perpendicularly to the film plane, whereas the Co magnetization is in the film plane. Comparison of the as-grown magnetic domain images of the Co and Ni layers reveals the influence of the magnetostatic stray fields from Ni domain walls on the Co domain pattern as a lateral displacement of the Co domain wall position compared to the Ni domain walls. The effect is quantified by comparing to the effect of external magnetic fields, and is found to be equivalent to about 250 Oe. Micromagnetic simulations using the Landau-Lifshitz-Gilbert equation confirm that size of the Ni domain wall stray field interaction.