We present a detailed x-ray magnetic circular dichroism (XMCD) study of the magnetic properties of Gd-doped EuO thin films, synthesized via molecular-beam epitaxy with Gd doping levels up to over 12%. The impact of Gd doping on the electronic and magnetic behavior of EuO is studied using XMCD and magnetometry. Gd doping significantly enhances the Curie temperature (πC) from 69 K in undoped EuO to over 120 K, driven by increased carrier density, while preserving the high quality of the single-crystalline films. At higher doping levels, a plateau in πC is observed, which is attributed to the formation of Eu-Gd nearest-neighbor pairs that limit dopant activation. We also observe a distinctive βdouble-domeβ structure in the temperature-dependent magnetization, which we attribute to both the ferromagnetic ordering of Eu 4β’π moments at lower temperatures and the influence of conduction electrons via 4β’πβ5β’π exchange interactions at higher temperatures. These findings provide key insights into the mechanisms of carrier-induced magnetic transitions.
Materials by design for sustainable solutions in the energy, medical, transport, and engineering sectors
