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

The optical and magneto-optical spectra of neodymium NaCl-type compounds Nd X (X = S, Se, and Te) and Nd3S4 With Th3P4 crystal structure are investigat ed theoretically using an energy-band approach in combination with the line ar-response formalism. The energy band structure is obtained within the loc al spin-density approximation (LSDA), and within its extension Which explic itly takes into account the onsite 4f Coulomb interaction U (LSDA + U). Alt hough the LSDA predicts a large Kerr rotation in the compounds under consid eration, we find that the LSDA + U gives a better description of the Kerr s pectra of NdS and Nd3S4 The origin of the Kerr rotation realized in the com pounds is examined. [S0163-1829(99)08721-4].