Large orbital moments and internal magnetic fields in lithium nitridoferrate(I).

The iron nitridometalates Li2[(Li(1-x)Fe(I)(x))N] display ferromagnetic ordering and spin freezing. Large magnetic moments up to 5.0mu(B)/Fe are found in the magnetization. In Mössbauer effect studies huge hyperfine magnetic fields up to 696 kOe are observed at specific Fe sites. These extraordinary fields and moments originate in an unusual ligand field splitting for those Fe species leading [within local spin density approximation (LSDA)] to a localized orbitally degenerate doublet. Including spin-orbit interaction and strong intra-atomic electron correlation (LDA+SO+U) gives rise to a large orbital momentum.

The Valence States of Nickel, Tin, and Sulfur in the Ternary Chalcogenide Ni(3)Sn(2)S(2)-XPS, (61)Ni and (119)Sn Mössbauer Investigations, and Band Structure Calculations.

The hitherto controversial valence states of nickel and tin in the ternary chalcogenide Ni(3)Sn(2)S(2) (see structure) have been determined by photoelectron and Mössbauer spectroscopy ((61)Ni, (119)Sn). Results from band structure calculations confirmed that this shandite phase is a metal and that the approximate distribution of the valence electrons is (Ni(0))(3)(Sn(1)(II))(Sn(2)(II))(S(II-))(2).