Ernst Z. Kurmaev

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The origin of the gap in NiS 2 as well as the pressure-and doping-induced metal-insulator transition in the NiS 2−x Se x solid solutions are investigated both theoretically using the first-principles band structures combined with the dynamical mean-field approximation for the electronic correlations and experimentally by means of infrared and x-ray(More)
LDA+DMFT (Local Density Approximation combined with Dynamical Mean-Field Theory) computation scheme has been used to calculate spectral properties of LaFeAsO – the parent compound of the new high-T c iron oxypnictides. The average Coulomb repulsion ¯ U =3÷4 eV and Hund's exchange J=0.8 eV parameters for iron 3d electrons were calculated using the first(More)
  • E Z Kurmaev, V M Cherkashenko, Yu M Yarmoshenko, St Bartkowski, A V Postnikov, M Neumann +5 others
  • 2008
A VO 2 single-crystal has been subject of a combined investigation by high resolution x-ray photoelectron spectroscopy (XPS), x-ray emission spectroscopy (XES) with both electron and energy-selective x-ray excitation (VLα-, VKβ 5-and OKα-emission) and x-ray absorption spectroscopy (XAS) (O1s). We performed first principles tight-binding LMTO band structure(More)
We present synchrotron-excited oxygen x-ray K-emission spectroscopy ͑O K␣ XES͒ and oxygen x-ray absorption spectroscopy ͑O 1s XAS͒ spectra of transition-metal ͑TM͒ oxides MnO, CoO, and NiO. The comparison of oxygen K-emission and absorption spectra to valence band photoemission and bremsstrahlung isochromat spectra measurements shows that O 1s XAS is not(More)
The electronic structure of Zn 1−x Co x O ͑x = 0.02, 0.06, and 0.10͒ diluted magnetic semiconductors is investigated using soft x-ray emission spectroscopy and first-principles calculations. X-ray absorption and emission measurements reveal that most Co dopants are incorporated at the Zn sites and that free charge carriers are absent over a wide range of Co(More)
The electronic structure of spinel-type Cu 1Ϫx Ni x Rh 2 S 4 (xϭ0.0, 0.1, 0.3, 0.5, 1.0͒ and CuRh 2 Se 4 compounds has been studied by means of x-ray photoelectron ͑XPS͒ and fluorescent spectroscopy. and Se M 2,3 x-ray emission spectra ͑XES͒ were measured near thresholds at Beamline 8.0 of the Lawrence Berkeley Laboratory's Advanced Light Source. XES(More)
This study reports a scalable and economical method to open a band gap in single layer graphene by deposition of cobalt metal on its surface using physical vapor deposition in high vacuum. At low cobalt thickness, clusters form at impurity sites on the graphene without etching or damaging the graphene. When exposed to oxygen at room temperature, oxygen(More)
Resonant x-ray emission spectroscopy (XES) measurements at Fe L(2,3) edges and electronic structure calculations for LiFeAs and NaFeAs are presented. Experiment and theory show that in the vicinity of the Fermi energy, the density of states is dominated by contributions from Fe 3d states. The comparison of Fe L(2,3) XES with spectra of related FeAs(More)
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