B. N. Harmon

K-Doping Dependence of the Fermi Surface of the Iron-Arsenic Ba1-xKxFe2As2 Superconductor Using Angle-Resolved Photoemission Spectroscopy

C. Liu, G. D. Samolyuk, Y. Lee, N. Ni, T. Kondo, A. F. Santander-Syro, 3 S. L. Bud’ko, J. L. McChesney, E. Rotenberg, T. Valla, A. V. Fedorov, P. C. Canfield, B. N. Harmon, and A. Kaminski Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA Laboratoire Photons Et Matière, UPR-5 CNRS, ESPCI, 10 rue Vauquelin, 75231 Paris cedex 5, France Labratoire de Physique des Solides, UMR-8502 CNRS, Université Paris-Sud, Bât. 510, 91405 Orsay, France Advanced Light Source, Berkeley National Laboratory, Berkeley, California 94720, USA Condensed Matter Physics and Materials Science Dept., Brookhaven National Laboratory, Upton, New York 11973, USA (Dated: June 20, 2008)

Band structure of cubic NaxWO3

Abstract The band structures of cubic WO3 and NaWO3 have been calculated, and they are shown to be nearly identical, demonstrating the validity of the rigid band model for different sodium concentrations. To elucidate the nature of the bonding, the density of states is decomposed into its s, p, and d contributions from each atomic site.

Calculation of magneto-optical properties for 4f systems: LSDA + Hubbard U results

The electronic structure of gadolinium metal and CeSb has been calculated using a density functional method which explicitly includes the Coulomb parameter U for the 4f-electrons. The calculated density of states, total energies, Fermi surface, and magneto-optical properties are in better agreement with experiment than those obtained with the standard local density technique.

Lattice collapse and quenching of magnetism in CaFe[subscript 2]As[subscript 2] under pressure: A single-crystal neutron and x-ray diffraction investigation

Single-crystal neutron and high-energy x-ray diffraction measurements have identified the phase lines corresponding to transitions among the ambient-pressure paramagnetic tetragonal (T), the antiferromagnetic orthorhombic (O), and the nonmagnetic collapsed tetragonal (cT) phases of

Polarized neutron study of CeSn3 (invited)

{\text{CaFe}}_{2}{\text{As}}_{2}

Aspects of spin dynamics and magnetic interactions

. We find no evidence of additional structures for pressures of up to 2.5 GPa (at 300 K). Both the T-cT and O-cT transitions exhibit significant hysteresis effects, and we demonstrate that coexistence of the O and cT phases can occur if a nonhydrostatic component of pressure is present. Measurements of the magnetic diffraction peaks show no change in the magnetic structure or ordered moment as a function of pressure in the O phase, and we find no evidence of magnetic ordering in the cT phase. Band-structure calculations show that the transition into the cT phase results in a strong decrease in the iron

Effect of local Coulomb interactions on the electronic structure and exchange interactions in Mn12 magnetic molecules

3d

Incommensurate Spin-Density Wave Order in Electron-Doped BaFe2As2 Superconductors

density of states at the Fermi energy, consistent with a loss of the magnetic moment.

Mechanisms of Decoherence in Weakly Anisotropic Molecular Magnets

Over the past several years there has been considerable interest in materials exhibiting a nonintegral valence. As a result the properties of cerium metal and its compounds have been the subject of many theoretical and experimental investigations. In the present experiment polarized neutron scattering techniques have been used to study the spatial distribution and temperature dependence of the magnetization induced in a single crystal of CeSn3 by a magnetic field of 42.5 kG. In the 40–300 K temperature range the measured magnetic form factor is in good agreement with the 4f magnetic form factor of Ce3+. Below 40 K, on the other hand, the magnetic form factor measurements suggest that the induced magnetization contains a large component of 5d electronic character of eg symmetry, which can account, at least partly, for the increase in the magnetic susceptibility of CeSn3 at low temperatures. The results will be discussed in terms of a model in which the 4f level is positioned slightly above the Fermi energy...

Many-Spin Interactions and Spin Excitations in Mn12

Abstract Non-collinear magnetic alignment is somewhat unusual for equilibrium, and those systems exhibiting such ground states are frequently `victims’ of competing forces. For non-equilibrium, or dynamical systems (e.g. T >0) non-collinear alignment is universal. We discuss such systems and present some basic formalism for evaluating from first principles the equation of motion and related relevant properties. Considerable discussion is also devoted to obtaining from first principles, parameters for model magnetic Hamiltonians. These models represent a convenient way to gain insight and to approximately evaluate magnetic interactions for very complex systems.