The Energy Band Structure of Corundum

Ėvarestov, R. A.; Ermoshkin, A. N.; Lovchikov, V. A.

doi:10.1002/pssb.2220990142

Cited by 56 publications

(9 citation statements)

References 14 publications

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“…The quadrupole coupling tensors (including the sign) at O and Al are known from 27 Al and 17 O nuclear quadrupole resonance spectroscopy [4][5][6]. There are also many theoretical investigations on the EFG tensor [7][8][9][10][11][12][13][14] reported in the literature that can be used to test results from this work.…”

Section: Introductionmentioning

confidence: 94%

Investigations of Nuclear Quadrupole Interaction in BaMgAl10O17:Eu2+

Stephan¹,

Schmidt²,

Mishra³

et al. 2001

Zeitschrift Für Physikalische Chemie

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BAM / Barium Magnesium Aluminate / Nuclear Quadrupole Interaction / Phosphor / Electronic Band Structure / Luminescence / EuropiumLocal environments of divalent europium ions in β-lattice of barium magnesium aluminate, BaMgAl 10 O 17 (BAM) have been investigated using a recently developed ab initio band structure method. This method is a variant of the full potential LMTO method. The reliability of this method for calculating electric field gradient (EFG) was tested in the case of aluminum oxide in corundum structure. The calculated EFGs at both cation and anion sites compare satisfactorily with those from other ab initio methods and from recent measurements. The nuclear quadrupole coupling constants for Eu 2+ calculated by this method at various possible sites in BAM, when compared to recently measured 151 Eu Mössbauer spectroscopy results, suggest three locations for Eu 2+ : a Beevers-Ross site, a mid-oxygen site and an anti-Beevers-Ross site. Energetically, the anti-Beevers-Ross site appears to be more stable than the other two sites.

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Section: Introductionmentioning

confidence: 94%

Investigations of Nuclear Quadrupole Interaction in BaMgAl10O17:Eu2+

Stephan¹,

Schmidt²,

Mishra³

et al. 2001

Zeitschrift Für Physikalische Chemie

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“…The spectra of bulk corundum has been widely described by Evarestov et al [55]. According to these authors, the band gap of corundum is 9.5 eV and the excitonic peak appears at 9.25 eV.…”

Section: Nature Of Optical Excitationsmentioning

confidence: 99%

Character of the electronic ground state and of charge‐transfer excited states in ionic solids: An ab initio cluster model approach

Casanovas

Lorda

Sousa

et al. 1994

Int J of Quantum Chemistry

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The electronic structure of the ground electronic state and of some special charge-transfer excited states in ionic solids is examined from the ab initio cluster model approach. Different ab initio wave functions, including a frozen orbital approach, the Hartree-Fock self-consistent field, and multireference configuration interaction wave functions, are considered and analyzed using different theoretical techniques. We explicitly consider some alkaline-earth oxides such as CaO, a more difficult case such as Al2O3, a transitionmetal oxide such as NiO, and a system with a more complicated structure such as KNiF3. Analysis of ab initio wave functions in terms of valence bond components shows that all these compounds are largely ionic, thus supporting the simple picture arising from the ionic model. However, the nature of the excited states is more complex. Alkaline-earth oxides lowest excited states are essentially described as charge-transfer excitations dominated by a single resonant valence bond structure and the calculated energy difference is comparable to the experimental optical gap. In the case of Al2O3, the electronic spectra presents excitonic features and the local charge-transfer excitation excited states provide a reasonable representation of these phenomena. Finally, several different valence bond structures are present in the lowest electronic states of KNiF3.

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“…Its peculiar crystal structure and wide-ranging applications have drawn both theoretical and experimental interest. Indeed, the electronic structure of aluminum oxide has been widely studied both theoretically [16][17][18][19][20][21][22] and experimentally 23,24 However, there is no general agreement theoretically 17,16,19 and experimentally. 23,25-29 on its band structure details, and particularly few of them have concerned the momentum distribution aspect of its valence-band electrons.…”

Section: Introductionmentioning

confidence: 99%

Electronic-structure investigation of oxidized aluminum films with electron-momentum spectroscopy

et al. 1996

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Electron-momentum spectroscopy ͑EMS͒ or (e,2e) measurements with oxidized aluminum thin films have been performed. Due to the surface sensitive nature of the EMS spectrometer employed, the measured (e,2e) events come from the front oxidized layer as viewed by the electron detectors. The measurements show clearly two major features in the spectral momentum density distribution and they are related to the upper valence band and the lower valence band of aluminum oxide. The first is a ''dual parabola'' energy-momentum dispersion pattern spanning about 8 eV in the upper valence band. This dual parabola pattern has been qualitatively reproduced by a linear muffin-tin orbital ͑LMTO͒ calculation on spherically averaged ␣-Al 2 O 3 with nearly the same energy span. In the lower valence band, the LMTO calculation indicates a dispersion spanning about 5 eV, and the measured spectral momentum density plot shows a similar ''bowl'' shape but with less dispersion. The possible causes that blur the dispersion in the lower valence band are discussed. Other features in the spectral momentum density distribution are also discussed and compared with the LMTO calculation. ͓S0163-1829͑96͒08147-7͔

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The Energy Band Structure of Corundum

Cited by 56 publications

References 14 publications

Investigations of Nuclear Quadrupole Interaction in BaMgAl10O17:Eu2+

Investigations of Nuclear Quadrupole Interaction in BaMgAl10O17:Eu2+

Character of the electronic ground state and of charge‐transfer excited states in ionic solids: An ab initio cluster model approach

Electronic-structure investigation of oxidized aluminum films with electron-momentum spectroscopy

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