X-ray Magnetic Circular Dichroism Spectra for Uranium Monochalcogenides, UQ (Q = S, Se, and Te) from First Principles

In this study, by applying relativistic full potential density functional theory with the generalized gradient approximation (GGA), GGA + U, and GGA + OP (orbital polarization) methods, we have investigated the magnetic properties of uranium monochalcogenides, UQ (Q = S, Se, and Te). The emphasis here is to calculate X-ray magnetic circular dichroism (XMCD) spectra of U in UQ systems at the U M45, N45, and L23 edges and compare the spectra as well as deduced parameters such as spin, orbital, and total magnetic moments with the available experimental and computational results. The effect of the Hubbard (U) parameter on the 5f electrons of uranium is also scrutinized to probe the electron correlation effects in UQ for their electronic and magnetic properties. The spin and orbital sum rule analyses have been carried out on the computed U M45 and N45 XMCD spectra. The corresponding spin, orbital, and total magnetic moments and the ratio of orbital and spin magnetic moments determined for UQ systems are found to be in good agreement with experiments when we use the GGA + OP method.