Abstract
The imaginary part of the dielectric function $\text{Im}[\ensuremath{\epsilon}(\ensuremath{\omega})]$ of rocksalt GdN is calculated using the linear muffin-tin orbital method in the atomic sphere approximation. The local spin-density approximation with added Hubbard-$U$ terms $(\text{LSDA}+\text{U})$ is used to include orbital-dependent Coulomb interactions for the $\text{Gd}\text{ }4f$ and $5d$ orbitals. The spin-orbit coupling is shown to affect the dominant spin character of the bands only negligibly so that we can analyze the optical interband transitions as being between bands of equal spin only. The separate band-to-band contributions to $\text{Im}[\ensuremath{\epsilon}(\ensuremath{\omega})]$ are analyzed as well as the origin of the main peaks in the Brillouin zone, allowing us to identify critical-point transitions. We find that the transitions from the upper valence band (doubly degenerate along some portions of the Brillouin zone) dominate the spectrum. The transitions to the minority-spin $f$ bands occur as a double peak near 5.5--6 eV. The corresponding transitions of the filled $f$ bands to the conduction band have negligible contribution. Many of the peaks correspond to complex avoided band crossings in the conduction band where local maxima and minima occur.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.