Fe3O4 is a mixed-valence strongly correlated transition metal oxide which displays the intriguing metal to insulator Verwey transition. Here we investigate the electronic and magnetic structure of Fe3O4 by a unique combination of high-resolution Fe 2p3d resonant inelastic scattering magnetic circular (RIXS-MCD) and magnetic linear (RIXS-MLD) dichroism. We show that by coupling the site selectivity of RIXS with the magnetic selectivity imposed by the incident polarization handedness, we can unambiguously identify spin-flip excitations and quantify the exchange interaction of the different sublattices. Furthermore, our RIXS-MLD measurements show spin-orbital excitations that exhibit strong polarization and magnetic field dependence. Guided by theoretical simulations, we reveal that the angular dependence arises from a strong interplay between trigonal crystal-field, magnetic exchange and spin-orbit interaction at the nominal Fe2+ sites. Our results highlight the capabilities of RIXS magnetic dichroism studies to investigate the ground state of complex systems where in-equivalent sites and bonds are simultaneously present.
@article{arxiv.1811.04836,
title = {Site selective spin and orbital excitations in Fe3O4},
author = {H. Elnaggar and R. Wang and S. Lafuerza and E. Paris and A. C. Komarek and H. Guo and Y. Tseng and D. McNally and F. Frati and M. W. Haverkort and M. Sikora and T. Schmitt and F. M. F. de Groot},
journal= {arXiv preprint arXiv:1811.04836},
year = {2018}
}