Magnetic properties of thin Eu films on Gd(0001) studied by magnetic circular dichroism in photoemission

摘要

The magnetic roder of ultra-thin Eu films on Gd(0001) was studied in an element-specific and layer-resolved way using magnetic circular dichroism (MCD) in 4f photoemission (PE). It was found that Eu films up to 2 monolayers (ML) exhibit a high net magnetization parallel to that of the Gd substrate. For Eu coverages exceeding 2ML, the ferromagnetic alignment of the Eu moments breaks down, except for the Eu interface layer. A comparison of the temperature dependences of the Eu-4f and Gd-4f MCD-PE signals for 1-Ml-Eu/Gd(0001) with the results of a layer-resolved mean-field calculation results in values for the exchange coupling constants within the Eu monolayer as well as between Eu and the Gd substrate.