Electronic Structure of Molybdenum Dioxide Calculated by the X_α Method

Abstract

The discrete variational-Xcr method employing a [Mo,~,,,]~~-cluster is applied to electronic-structure and density of states calculations of rutile family MOO,. Level profiles obtained are generally in good agreement with the optical conductivity data and observations by photoelectron spectroscopy. The splitting of the Mo 4d predominant levels just below the EF level is attributed to the formation of a partially filledMo-O(x*) type band which is lower in the binding energy by % 0.7 eV than the completely filled Mo-Mo (o)

A metallic molybdenum suboxide buffer layer for organic electronic devices

“…The valence spectrum closely resembles that of MoO 2 , 25,26 which is known to be a metallic oxide, with a resistivity of 8.8ϫ 10 −5 ⍀ cm. 27 The spectrum has a peak centered at 1.6 eV, attributed to O 2p states, 26 and a broad feature crossing the Fermi level attributed to Mo 4d states. 26 The work functions of the three substrates were determined from the photoemission secondary-electron cut-off, as shown in the top panel of Fig.…”

“…24 In contrast to stoichiometric MoO 3 , the valence spectrum of the reduced oxide shows occupied states extending up to the Fermi level, implying the material has no band gap ͑i.e., metallic character͒. The valence spectrum closely resembles that of MoO 2 , 25,26 which is known to be a metallic oxide, with a resistivity of 8.8ϫ 10 −5 ⍀ cm. 27 The spectrum has a peak centered at 1.6 eV, attributed to O 2p states, 26 and a broad feature crossing the Fermi level attributed to Mo 4d states.…”

Electronic structure of face-centred cubic MoO2: A comparative study by the full potential linearized augmented plane wave method, X-ray emission spectroscopy and X-ray photoelectron spectroscopy

“…The aforementioned experimental studies reveal the presence of +4 oxidation states of Mo (in addition to Mo 6+ ions) on the surface of molybdenum dioxide and exhibit a formation of an additional near-Fermi sub-band on the XPS valence-band spectra when going from MoO 3 to MoO 2 . Electronic properties of molybdenum dioxide in a hypothetical high-symmetry rutile-like structure were calculated by the discrete variational-X␣ (DV-X␣) method [38,39], while Eyert et al [40] have made band-structure calculations of monoclinic MoO 2 based on density functional theory within the local density approximation and using the augmented spherical wave (DFT-LDA-ASW) method. Due to results of the DFT-LDA-ASW calculations [40], the valence band of MoO 2 is dominated by strong hybridization of the O 2p and crystal-field-split Mo 4d states, and the near-Fermi sub-band of the compound originates almost exclusively from Mo 4d(t 2g ) orbitals.…”

Formation energies of rutile metal dioxides using density functional theory

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] In addition, some theoretical studies, at different levels of theory, have confirmed the structural results of the experiments, showing enhanced stability of the rutile phase for most metal dioxides. [20][21][22][23] Rutile oxides are interesting in connection with electrochemical and photoelectrochemical water splitting, [24][25][26][27] and recently the surface redox processes on, e.g., RuO 2 and TiO 2 have been treated using density functional theory ͑DFT͒. 28,29 The question remains whether standard DFT-generalized gradient approximation ͑GGA͒ ͑Refs.…”