Properties Of 3d Transition Metals Research Articles

Binding properties of 3d transition metals in a generalized density-functional theory.

In a preceding paper we have reported on band-gap corrections in semiconductors and insulators that were calculated within a generalized density-functional (GDF) theory. Similar to an earlier idea of Gunnarsson and Jones, we describe exchange and correlation effects by suitably modeled pair-correlation factors. They are subject to certain sum rules that ensure the absence of self-interaction in the electron-electron interaction integrals. The resulting exchange-correlation potential in the GDF-derived one-particle equations is «nonlocal» (NL), as distinct from its local-density approximation (LDA) analogue, which has so far almost exclusively been used in performing DF calculations on solids

Antiferromagnetism in 3dtransition metals

Total-energy band calculations using the local-spin-density approximation, the augmented-spherical-wave method, and the fixed-spin-moment procedure are used to investigate the volume dependence of the magnetic and electronic properties of 3d transition metals constrained to cubic environments in one-atom or two-atom unit cells. The calculations cover a range of volumes spanning the nonmagnetic-ferromagnetic and the nonmagnetic-antiferromagnetic transitions. We find antiferromagnetism in bcc vanadium at expanded volumes, show that bcc chromium has a first-order transition from nonmagnetic to antiferromagnetic behavior at a 2% expanded lattice constant, and find that previously reported antiferromagnetic solutions for bcc iron are unstable. Comments are made on when antiferromagnetism occurs and on the many-atom ground states for chromium and manganese.

Ligand field spectra of the 3d transition metals in molten cesium, sodium, potassium/trifluoroacetate

Results are reported of electronic absorption spectroscopic studies that were carried out to investigate the ligand field properties of 3d transition metals in molten alkali-metal trifluoroacetates. The purpose of these studies was to examine the nature of transition-metal trifluoroacetate complexes in a medium free of other ligands and to explore the solvent properties of molten trifluoroacetates relative to other glassy and molten salts and to water. 12 references, 2 figures, 1 table.

Optical properties of 3d transition metals in II–VI compounds

The physics of internal and charge transfer transitions involving 3d impurities in T d and C 3v crystal lattices of II–VI compounds is reviewed. Starting from the simple model of point-like electrostatic charges, a diversity of additional interactions is considered, such as symmetry lowering by internal or external fields, spin-orbit coupling, dynamic effects, and covalency. Some problems of d-d transition probabilities are touched on.

Optical Properties of 3d Transition Metals: V, Cr, Fe and Ni

Complex dielectric function e (0, ω) and energy-loss function -Im [ e (0, ω) -1 ] of the 3d transition metals (V, Cr, Fe and Ni) are calculated within RPA with the use of the energy values and the wave functions determined by the APW method in the energy range 0–40 eV and are compared with experiment. The theoretical results of -Im [ e (0, ω) -1 ] are in fairly good agreement with experiment in the energy range 10–40 eV. But agreement between theoretical e (0, ω)'s and experimental ones is not so good in the energy range 1–8 eV as in the case of the 4d transition metals (Nb and Mo).