Soft x-ray magnetic circular dichroism study on Gd-doped EuO thin films

We report on the growth and magnetic properties of Gd-doped EuO thin films. We prepared samples with Gd concentrations up to 11% by means of molecular beam epitaxy under distillation conditions. Using soft x-ray magnetic circular dichroism at the Eu and Gd M4,5 edges, we found that TC ranges from 69 K for pure stoichiometric EuO to about 170 K for films with the optimal Gd doping of around 4%. The doping dependence of TC has been investigated and compared with available theoretical predictions. We also show that the Gd magnetic moment couples ferromagnetically to that of Eu.