Electronic structure and x-ray magnetic circular dichroism inYbAgCu4andYbInCu4

Abstract

X-ray absorption and magnetic circular dichroism spectra at the ${L}_{3}$ edge of Yb have been studied theoretically in the mixed-valent compounds ${\mathrm{YbAgCu}}_{4}$ and ${\mathrm{YbInCu}}_{4}$ using the fully relativistic Dirac linear muffin-tin orbital band structure method. The effect of the spin-orbit (SO) interaction and Coulomb repulsion $U$ on the electronic structure of ${\mathrm{YbAgCu}}_{4}$ and ${\mathrm{YbInCu}}_{4}$ is examined in the frame of the local spin-density approximation (LSDA)+SO+$U$ method. The core-hole effect in the final states as well as the effect of the electric quadrupole ${E}_{2}$ and magnetic dipole ${M}_{1}$ transitions have been investigated. The calculated results are compared with available experimental data.