  Europium intermetallic compounds show a variety of different ground states
and anomalous physical properties due to the interactions between the localized
4f electrons and the delocalized electronic states. Europium is also the most
reactive of the rare earth metals which might be the reason why very few works
are concerned with the properties of Eu-based thin films. Here we address the
low-temperature magnetic properties of ferromagnetic EuPd$_2$ thin films
prepared by molecular beam epitaxy. The epitaxial (111)-oriented thin films
grow on MgO (100) with eight different domain orientations. We analyze the
low-temperature magnetic hysteresis behavior by means of micromagnetic
simulations taking the multi-domain morphology explicitly into account and
quantify the magnetic crystal anisotropy contribution. By ab initio
calculations we trace back the microscopic origin of the magnetic anisotropy to
thin film-induced biaxial strain.
