Transition-metal oxides in the self-interaction–corrected density-functional formalism

Knowledge about the formation energies of compounds is essential to derive phase diagrams of multicomponent phases with respect to elemental reservoirs. The determination of formation energies using common (semi-)local exchange-correlation approximations of the density functional theory (DFT) exhibits well-known systematic errors if applied to oxide compounds containing transition metal elements. In this work, we generalize, reevaluate, and discuss a set of approaches proposed and widely applied in the literature to correct for errors arising from the over-binding of the O2 molecule and from correlation effects of electrons in localized transition-metal orbitals. The DFT+U method is exemplarily applied to iron oxide compounds, and a procedure is presented to obtain the U values, which lead to formation energies and electronic band gaps comparable to the experimental values. Using such corrected formation energies, we derive the phase diagrams for LaFeO3, Li5FeO4, and NaFeO2, which are promising materials for energy conversion and storage devices. A scheme is presented to transform the variables of the phase diagrams from the chemical potentials of elemental phases to those of precursor compounds of a solid-state reaction, which represents the experimental synthesis process more appropriately. The discussed workflow of the methods can directly be applied to other transition metal oxides.

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FACILE CYCLOADDITION OF TRANSITION METAL OXIDES ONTO THE SIDEWALL OF BORON-DOPED FULLERENE

Surface Review and Letters ◽

10.1142/s0218625x09013025 ◽

2009 ◽

Vol 16 (04) ◽

pp. 525-532

Author(s):

ZI-RONG TANG

Keyword(s):

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Boron Doping ◽

Organic Base ◽

Functional Theory ◽

Boron Doped ◽

Ruthenium Tetraoxide

The viability of facile oxidation and cycloaddition of fullerene C 60 with ruthenium tetraoxide ( RuO 4) has been confirmed by means of density functional theory calculations. Owing to the powerful capability of RuO 4 as an oxidant, the addition process has been found to occur readily in the absence of organic base as a catalyst, which is in remarkable contrast to the base-catalyzed osmylation of C 60 with osmium tetraoxide ( OsO 4). Significantly, we have found that boron can be employed as an effective promoter for enhancing the cycloaddition and complexation of transition metal oxides, e.g. RuO 4 and OsO 4, with C 60, in which the base is not needed at all. Our results suggest that boron doping into the lattice of fullerenes and carbon nanotubes would provide a well-defined approach for anchoring transition metal oxides.

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Molecular Transition Metal Oxides: Ab Initio and Density Functional Electronic Structure Study of Tungsten Oxide Clusters

The Journal of Physical Chemistry A ◽

10.1021/jp992814b ◽

2000 ◽

Vol 104 (4) ◽

pp. 859-865 ◽

Cited By ~ 6

Author(s):

Athanassios C. Tsipis ◽

Constantinos A. Tsipis

Keyword(s):

Electronic Structure ◽

Transition Metal ◽

Metal Oxides ◽

Ab Initio ◽

Tungsten Oxide ◽

Transition Metal Oxides ◽

Density Functional ◽

Structure Study ◽

Molecular Transition

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Transition Metal Oxide-Diamond Interfaces for Electron Emission Applications

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.761 ◽

2013 ◽

Vol 740-742 ◽

pp. 761-764

Author(s):

Amit K. Tiwari ◽

Jonathan P. Goss ◽

Patrick R. Briddon ◽

Nicholas G. Wright ◽

Alton B. Horsfall ◽

...

Keyword(s):

Transition Metal ◽

Transition Metals ◽

Metal Oxides ◽

Electron Affinity ◽

Transition Metal Oxides ◽

Density Functional ◽

Chemical Species ◽

Negative Electron Affinity ◽

Diamond Surfaces ◽

Electron Emitters

Diamond surfaces with suitable adsorbed chemical species can exhibit both negative and positive electron affinities, arising from the complex electrostatic interplay between adsorbates and surface carbon atoms of diamond lattice. We presents the results of density functional calculations into the energetics and the electron affinity of diamond (100) surfaces terminated with the oxides of selected transition metals. We find that for a correct stoichiometry, oxides of transition metals, such as Ti and Zn, exhibit a large negative electron affinity of around 3 eV. The desorption of transition metal oxides is found to be highly endothermic. We therefore propose that transition metal oxides are promising for the surface coating of diamond-based electron emitters, as these exhibit higher thermal stability in comparison to the commonly used CsO terminations, while retaining the advantage of inducing a large negative electron affinity.

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Evaluation of optical band gaps and dopant state energies in transition metal oxides using oxidation-state constrained density functional theory

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/ac0cb8 ◽

2021 ◽

Author(s):

Calvin Ku ◽

Patrick Sit

Keyword(s):

Density Functional Theory ◽

Transition Metal ◽

Metal Oxides ◽

Oxidation State ◽

Transition Metal Oxides ◽

Density Functional ◽

Band Gaps ◽

Functional Theory ◽

Optical Band Gaps

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GW approximation study of late transition metal oxides: Spectral function clusters around Fermi energy as the mechanism behind smearing in momentum density

Modern Physics Letters B ◽

10.1142/s0217984916501621 ◽

2016 ◽

Vol 30 (14) ◽

pp. 1650162

Author(s):

S. M. Khidzir ◽

K. N. Ibrahim ◽

W. A. T. Wan Abdullah

Keyword(s):

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

Fermi Energy ◽

Momentum Density ◽

The Self ◽

Late Transition Metal ◽

Gw Approximation ◽

Self Energy ◽

Late Transition

Momentum density studies are the key tool in Fermiology in which electronic structure calculations have proven to be the integral underlying methodology. Agreements between experimental techniques such as Compton scattering experiments and conventional density functional calculations for late transition metal oxides (TMOs) prove elusive. In this work, we report improved momentum densities of late TMOs using the GW approximation (GWA) which appears to smear the momentum density creating occupancy above the Fermi break. The smearing is found to be largest for NiO and we will show that it is due to more spectra surrounding the NiO Fermi energy compared to the spectra around the Fermi energies of FeO and CoO. This highlights the importance of the positioning of the Fermi energy and the role played by the self-energy term to broaden the spectra and we elaborate on this point by comparing the GWA momentum densities to their LDA counterparts and conclude that the larger difference at the intermediate level shows that the self-energy has its largest effect in this region. We finally analyzed the quasiparticle renormalization factor and conclude that an increase of electrons in the [Formula: see text]-orbital from FeO to NiO plays a vital role in changing the magnitude of electron correlation via the self-energy.

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Investigations of Doping and Dissolution in Lithium Transition Metal Oxides Using Density Functional Theory Methods

ECS Meeting Abstracts ◽

10.1149/ma2016-03/2/452 ◽

2016 ◽

Keyword(s):

Density Functional Theory ◽

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

Density Functional ◽

Functional Theory

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Systematic beyond-DFT study of binary transition metal oxides

npj Computational Materials ◽

10.1038/s41524-019-0251-7 ◽

2019 ◽

Vol 5 (1) ◽

Cited By ~ 9

Author(s):

Subhasish Mandal ◽

Kristjan Haule ◽

Karin M. Rabe ◽

David Vanderbilt

Keyword(s):

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

Density Functional ◽

Mean Field Theory ◽

Mean Field ◽

Photoemission Spectroscopy ◽

Dft Methods ◽

Angle Resolved Photoemission Spectroscopy ◽

Arpes Data

AbstractVarious methods going beyond density functional theory (DFT), such as DFT+U, hybrid functionals, meta-GGAs, GW, and DFT-embedded dynamical mean field theory (eDMFT), have been developed to describe the electronic structure of correlated materials, but it is unclear how accurate these methods can be expected to be when applied to a given strongly correlated solid. It is thus of pressing interest to compare their accuracy as they apply to different categories of materials. Here we introduce a novel paradigm in which a chosen set of beyond-DFT methods is systematically and uniformly tested on a chosen class of materials. For a first application, we choose the target materials to be the binary transition metal oxides FeO, CoO, MnO, and NiO in their antiferromagnetic phase and present a head-to-head comparison of spectral properties as computed using the various methods. We also compare with available experimental angle-resolved photoemission spectroscopy (ARPES), inverse-photoemission spectroscopy, and with optical absorption. For the class of compounds studied here, we find that both B3LYP and eDMFT reproduce the experiments quite well, with eDMFT doing best, in particular when comparing with the ARPES data.

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