Fully relativistic spin-polarized LMTO calculations of the magneto-optical Kerr effect of d and f ferromagnetic materials.: II.: Neodymium chalcogenides

The optical and magneto-optical spectra of neodymium NaCl-type compounds NdX (X = S, Se, and Te) and Nd3S4 With Th3P4 crystal structure are investigated theoretically using an energy-band approach in combination with the linear-response formalism. The energy band structure is obtained within the local spin-density approximation (LSDA), and within its extension Which explicitly takes into account the onsite 4f Coulomb interaction U (LSDA + U). Although the LSDA predicts a large Kerr rotation in the compounds under consideration, we find that the LSDA + U gives a better description of the Kerr spectra of NdS and Nd3S4 The origin of the Kerr rotation realized in the compounds is examined. [S0163-1829(99)08721-4].