Magnetic state of EuN: X-ray magnetic circular dichroism at the Eu M4,5 and L2,3 absorption edges

We report M-4,M-5-and L-2,L-3-edge x-ray magnetic circular dichroism (XMCD) studies of the ion-specific magnetic polarization on Eu in europium mononitride. The absorption spectra at both edges show a main signal originating from Eu3+ with a well-separated small (similar to 2%) contribution from a Eu2+ valence state that we propose is associated with a small concentration of N vacancies. Magnetic polarization is observed in both 4f and 5d orbitals and for both valence states. The temperature and field dependence of the M-4,M-5-edge XMCD signal shows a van Vleck signature from Eu3+ (main EuN contribution) and a Brillouin paramagnetic signal from the small concentration of Eu2+ ions. In addition, the L-2,L-3 edge shows that the Eu3+ ions have 5d orbitals that are polarized both by intra-ion f-d exchange and by inter-ionic d-d exchange from neighboring Eu2+ ions. There is no evidence of magnetic order among the Eu ions at temperatures as low as 10 K.