Electronic structure and magnetic properties of Europium monochalcogenides ($\mathrm{Eu}X$, $X=\mathrm{O}$, S, Se, and Te) have been investigated by the full potential linear muffin-tin orbital method. The generalized gradient approximation (GGA) including on site Coulomb interaction of $5d$ and $4f$ states $(\mathrm{GGA}+U_d+U_f)$ has been used to describe the complicated properties of $\mathrm{Eu}X$. The $\mathrm{GGA}+U_f$ band structure underestimates the band gap. $\mathrm{GGA}+U_d+U_f$ gives better agreement in terms of band gap and the positions of $4f$ bands of $\mathrm{Eu}X$. $\mathrm{GGA}+U_d+U_f$ gives much improved Kerr spectra for all the $\mathrm{Eu}X$ over the standard LSDA and $\mathrm{GGA}+U_f$ spectra although the magnitude of the first peak is less satisfactory in the dielectric function spectra. The Coulomb correlation effects among $4f$ and $5d$ electrons of Eu play important role to determine the optical spectra of $\mathrm{Eu}X$.

• Received 20 February 2004

DOI:https://doi.org/10.1103/PhysRevB.70.115211