Electronic structure of B<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>2</mml:mn><mml:mi>p</mml:mi><mml:mi>σ</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi><mml:mi>π</mml:mi></mml:math>states in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">MgB</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mr

Nakamura, Jin; Nasubida, S.; Kabasawa, Eiki; Yamazaki, Hisashi; Yamada, Noriko; Kuroki, Kazuhiko; Watanabe, Masamitsu; Oguchi, Tamio; Lee, Sergey; Yamamoto, Atsushi; Tajima, S.; Umeda, Yuji; Minakawa, Shin; Kimura, Noriaki; Aoki, Haruyoshi; Otani, Shigeki; Shin, Shik; Callcott, T. A.; Ederer, D. L.; Denlinger, Jonathan D.; Perera, R. C. C.

doi:10.1103/physrevb.68.064515

Cited by 18 publications

(8 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When going from MgB 2 to Mg 0.8 Al 0.2 B 2 and AlB 2 , a substantial decrease of feature A is immediately obvious. This reduction of feature A which has already been reported in literature 25,[39][40][41][42][43] illustrates that the σ-bonded boron sp 2 states become gradually occupied upon Al doping and are finally located below E F for AlB 2 . Consistent with the shift of the maximum position towards the boron sites observed for the static deformation density of AlB 2 in Fig.…”

Section: Resultssupporting

confidence: 78%

Electronic Structure of Single-Crystalline Mg_xAl₁₋_xB₂ Probed by X-ray Diffraction Multipole Refinements and Polarization-Dependent X-ray Absorption Spectroscopy

et al. 2014

View full text Add to dashboard Cite

X-ray diffraction multipole refinements of single-crystalline MgxAl1−xB2 and polarizationdependent near-edge x-ray absorption fine structure at the B 1s edge reveal a strongly anisotropic electronic structure. Comparing the data for superconducting compounds (x = 0.8, 1.0) with those for the non-superconductor (x = 0) gives direct evidence for a rearrangement of the hybridizations of the boron pz bonds and underline the importance of holes in the σ-bonded covalent sp 2 states for the superconducting properties of the diborides. The data indicate that Mg is approximately divalent in MgB2 and suggest predominantly ionic bonds between the Mg ions and the two-dimensional B rings. For AlB2 (x = 0), on the other hand, about 1.5 electrons per Al atom are transferred to the B sheets while the residual 1.5 electrons remain at the Al site which suggests significant covalent bonding between the Al ions and the B sheets. This finding together with the static electron deformation density points to almost equivalent electron counts on B sheets of MgB2 and AlB2, yet with a completely different electron/hole distribution between the σ and π bonds.

show abstract

Section: Resultssupporting

confidence: 78%

Electronic Structure of Single-Crystalline Mg_xAl₁₋_xB₂ Probed by X-ray Diffraction Multipole Refinements and Polarization-Dependent X-ray Absorption Spectroscopy

et al. 2014

View full text Add to dashboard Cite

show abstract

“…[15][16][17][18] Single crystal MgB 2 and AlB 2 have been already characterized, 19 however high quality Al and C, substituted crystals with intermediate substitution levels, have only lately become available, enabling more detailed studies of the anisotropies. 10,11,20 In a recent de Haas-van Alphen study of Al substituted single crystal MgB 2 , 14 the authors found a 16% reduction in the number of band holes with 7.5% Al content, but were unable to derive a number for the band.…”

Section: Introductionmentioning

confidence: 99%

Electron-hole counts in Al-substitutedMgB2superconductors from x-ray Raman scattering

et al. 2008

View full text Add to dashboard Cite

We have investigated the electronic structure of Mg 0.83 Al 0.17 B 2 and MgB 2 single crystals using x-ray Raman scattering at the B-K edge. Utilizing the momentum transfer dependence of the scattering process, together with first-principles multiple scattering calculations, we have extracted the site and symmetry projected density of empty B states in Mg 0.83 Al 0.17 B 2 in the presence of a core hole. In comparison to the density of states for pure MgB 2 , we find the B--band hole count to decrease at the Fermi level by 35Ϯ 9%. The -band hole count is relatively stable with a 4 Ϯ 7% increase compared to MgB 2 . These results shed light on the role of band filling in lowering the T c . Our work opens an application area for x-ray Raman scattering and density of states extraction scheme in studies of doped systems.

show abstract

“…As the dipole selection rule between the 1s core level and the 2p state governs the transition, we can obtain the partial density of states (PDOS) of carbon 2p and of boron 2p separately, which can give important information on the mechanism of superconductivity. [10,11,12] Moreover, XES spectroscopy is a bulk sensitive probe, not a surface sensitive one like photoelectron spectroscopy.…”

mentioning

confidence: 99%

Holes in the Valence Band of Superconducting Boron-Doped Diamond Film Studied by Soft X-ray Absorption and Emission Spectroscopy

et al. 2008

Self Cite

View full text Add to dashboard Cite

Carbon-and boron-2p states of superconducting and non-superconducting boron-doped diamond samples are measured using soft X-ray emission and absorption spectroscopy. For the superconducting sample, a large density of hole states is observed in the valence band in addition to the states in the impurity band. The hole states in the valence band is located at about 1.3 eV below the valence band maximum regardless of the doping level, which cannot be interpreted within a simple rigid band model. Present experimental results, combined with the first principles calculations, suggest that superconductivity is to be attributed to the holes in the valence band.

show abstract

Electronic structure of B2pσandpπstates inMgB2

Cited by 18 publications

References 27 publications

Electronic Structure of Single-Crystalline Mg_xAl₁₋_xB₂ Probed by X-ray Diffraction Multipole Refinements and Polarization-Dependent X-ray Absorption Spectroscopy

Electronic Structure of Single-Crystalline Mg_xAl₁₋_xB₂ Probed by X-ray Diffraction Multipole Refinements and Polarization-Dependent X-ray Absorption Spectroscopy

Electron-hole counts in Al-substitutedMgB2superconductors from x-ray Raman scattering

Holes in the Valence Band of Superconducting Boron-Doped Diamond Film Studied by Soft X-ray Absorption and Emission Spectroscopy

Contact Info

Product

Resources

About

Electronic structure of B2pσandpπstates inMgB2

Cited by 18 publications

References 27 publications

Electronic Structure of Single-Crystalline MgxAl1−xB2 Probed by X-ray Diffraction Multipole Refinements and Polarization-Dependent X-ray Absorption Spectroscopy

Electronic Structure of Single-Crystalline MgxAl1−xB2 Probed by X-ray Diffraction Multipole Refinements and Polarization-Dependent X-ray Absorption Spectroscopy

Electron-hole counts in Al-substitutedMgB2superconductors from x-ray Raman scattering

Holes in the Valence Band of Superconducting Boron-Doped Diamond Film Studied by Soft X-ray Absorption and Emission Spectroscopy

Contact Info

Product

Resources

About

Electronic Structure of Single-Crystalline Mg_xAl₁₋_xB₂ Probed by X-ray Diffraction Multipole Refinements and Polarization-Dependent X-ray Absorption Spectroscopy

Electronic Structure of Single-Crystalline Mg_xAl₁₋_xB₂ Probed by X-ray Diffraction Multipole Refinements and Polarization-Dependent X-ray Absorption Spectroscopy