Electronic structure and x-ray magnetic circular dichroism in ferroelectric CaMnTi2O6

We study the electronic and magnetic properties of ferroelectric ${\mathrm{CaMnTi}}_{2}{\mathrm{O}}_{6}$ within density functional theory using the generalized gradient approximation (GGA) with the consideration of strong Coulomb correlations $(\mathrm{GGA}+U)$ in the framework of the fully relativistic spin-polarized Dirac linear muffin-tin orbital band structure method. The x-ray absorption spectra (XAS) and x-ray magnetic circular dichroism (XMCD) at the Mn, Ti ${L}_{2,3}$, and O $K$ edges have been investigated theoretically. The calculated results are in good agreement with experimental data. The core-hole effect in the final state as well as the effect of the electric quadrupole ${E}_{2}$ and magnetic dipole ${M}_{1}$ transitions have been investigated. The core-hole effect has improved the agreement with the experimental XAS and XMCD spectra at the Ti and Mn ${L}_{2,3}$ edges.