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Dicks OA, Shluger AL. Theoretical modeling of charge trapping in crystalline and amorphous Al 2O 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:314005. [PMID: 28585524 DOI: 10.1088/1361-648x/aa7767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The characteristics of intrinsic electron and hole trapping in crystalline and amorphous Al2O3 have been studied using density functional theory (DFT). Special attention was paid to enforcing the piece-wise linearity of the total energy with respect to electron number through the use of a range separated, hybrid functional PBE0-TC-LRC (Guidon et al 2009 J. Chem. Theory Comput. 5 3010) in order to accurately model the behaviour of localized states. The tuned functional is shown to reproduce the geometric and electronic structures of the perfect crystal as well as the spectroscopic characteristics of MgAl hole centre in corundum α-Al2O3. An ensemble of ten amorphous Al2O3 structures was generated using classical molecular dynamics and a melt and quench method and their structural characteristics compared with the experimental data. The electronic structure of amorphous systems was characterized using the inverse participation ratio method. Electrons and holes were then introduced into both crystalline and amorphous alumina structures and their properties calculated. Holes are shown to trap spontaneously in both crystalline and amorphous alumina. In the crystalline phase they localize on single O ion with the trapping energy of 0.38 eV. In amorphous phase, holes localize on two nearest neighbour oxygen sites with an average trapping energy of 1.26 eV, with hole trapping sites separated on average by about 8.0 Å. No electron trapping is observed in the material. Our results suggest that trapping of positive charge can be much more severe and stable in amorphous alumina rather than in crystalline samples.
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Affiliation(s)
- Oliver A Dicks
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
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Ramo DM, Shluger AL. Structure and spectroscopic properties of oxygen divacancy in yttrium-stabilized zirconia. ACTA ACUST UNITED AC 2008. [DOI: 10.1088/1742-6596/117/1/012022] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Jacob PW, Kotomin EA, Stashans A, Tale IA. Mechanism of self-trapped hole motion in corundum crystals. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/13642819308207692] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- P. W.M. Jacob
- a Centre for Chemical Physics , The University of Western Ontario , London , N6A3K7 , Canada
| | - E. A. Kotomin
- a Centre for Chemical Physics , The University of Western Ontario , London , N6A3K7 , Canada
- b Institute for Solid State Physics, University of Latvia , 226098 , Riga , Latvia
| | - A. Stashans
- b Institute for Solid State Physics, University of Latvia , 226098 , Riga , Latvia
| | - I. A. Tale
- b Institute for Solid State Physics, University of Latvia , 226098 , Riga , Latvia
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Catlow CRA, French SA, Sokol AA, Thomas JM. Computational approaches to the determination of active site structures and reaction mechanisms in heterogeneous catalysts. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2005; 363:913-36; discussion 1035-40. [PMID: 15901543 DOI: 10.1098/rsta.2004.1529] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We apply quantum chemical methods to the study of active site structures and reaction mechanisms in mesoporous silica and metal oxide catalysts. Our approach is based on the use of both molecular cluster and embedded cluster (QM/MM) techniques, where the active site and molecular complex are described using density functional theory (DFT) and the embedding matrix simulated by shell model potentials. We consider three case studies: alkene epoxidation over the microporous TS-1 catalyst; methanol synthesis on ZnO and Cu/ZnO and C-H bond activation over Li-doped MgO.
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Affiliation(s)
- C R A Catlow
- Davy Faraday Research Laboratory, The Royal Institution of Great Britain, 21 Albemarle Street, London W1S 4BS, UK.
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Herschend B, Baudin M, Hermansson K. A combined molecular dynamics+quantum mechanics method for investigation of dynamic effects on local surface structures. J Chem Phys 2004; 120:4939-48. [PMID: 15267356 DOI: 10.1063/1.1635802] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A combined molecular dynamics (MD)+quantum mechanics (QM) method for studying processes on ionic surfaces is presented. Through the combination of classical MD and ab initio embedded-cluster calculations, this method allows the modeling of surface processes involving both the structural and dynamic features of the substrate, even for large-scale systems. The embedding approach used to link the information from the MD simulation to the cluster calculation is presented, and rigorous tests have been carried out to ensure the feasibility of the method. The electrostatic potential and electron density resulting from our embedded-cluster model have been compared with periodic slab results, and confirm the satisfying quality of our embedding scheme as well as the importance of applying embedding in our combined MD+QM approach. We show that a highly accurate representation of the Madelung potential becomes a prerequisite when the embedded-cluster approach is applied to temperature-distorted surface snapshots from the MD simulation.
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Affiliation(s)
- Bjorn Herschend
- Department of Materials Chemistry, The Angstrom Laboratory, Uppsala University, Box 538, S-751 21 Uppsala, Sweden
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Sherwood P, de Vries AH, Guest MF, Schreckenbach G, Catlow CA, French SA, Sokol AA, Bromley ST, Thiel W, Turner AJ, Billeter S, Terstegen F, Thiel S, Kendrick J, Rogers SC, Casci J, Watson M, King F, Karlsen E, Sjøvoll M, Fahmi A, Schäfer A, Lennartz C. QUASI: A general purpose implementation of the QM/MM approach and its application to problems in catalysis. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0166-1280(03)00285-9] [Citation(s) in RCA: 642] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Sushko PV, Gavartin JL, Shluger AL. Electronic Properties of Structural Defects at the MgO (001) Surface. J Phys Chem B 2002. [DOI: 10.1021/jp0129481] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter V. Sushko
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
| | - Jacob L. Gavartin
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
| | - Alexander L. Shluger
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
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French SA, Sokol AA, Bromley ST, Catlow CRA, Rogers SC, King F, Sherwood P. From CO2 to Methanol by Hybrid QM/MM Embedding. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20011203)113:23<4569::aid-ange4569>3.0.co;2-f] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kantorovich LN. An embedded-molecular-cluster method for calculating the electronic structure of point defects in non-metallic crystals. II. Structural elements in the form of molecules. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3719/21/29/005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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An approach for inclusion of crystal polarization in embedded cluster calculations: application to CaF2. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00300-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Johnson MA, Stefanovich EV, Truong TN. An ab Initio Study on the Oxidative Coupling of Methane over a Lithium-Doped MgO Catalyst: Surface Defects and Mechanism. J Phys Chem B 1997. [DOI: 10.1021/jp970012f] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Thanh N. Truong
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
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Kantorovich LN, Shluger AL. Polarization of a semi-infinite crystal by a point defect at the surface. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:136-147. [PMID: 9981957 DOI: 10.1103/physrevb.53.136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Shluger AL, Puchin VE, Suzuki T, Tanimura K, Itoh N. Optical transitions of the H centers in alkali halides. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:4017-4028. [PMID: 9981528 DOI: 10.1103/physrevb.52.4017] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Kotomin EA, Stashans A, Kantorovich LN, Lifshitz AI, Popov AI, Tale IA, Calais J. Calculations of the geometry and optical properties of FMg centers and dimer (F2-type) centers in corundum crystals. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:8770-8778. [PMID: 9977512 DOI: 10.1103/physrevb.51.8770] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Puchin V, Shluger A, Nakai Y, Itoh N. Theoretical study of Na-atom emission from NaCl (100) surfaces. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:11364-11373. [PMID: 10009989 DOI: 10.1103/physrevb.49.11364] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Shluger AL, Wilson RM, Williams RT. Theoretical and experimental investigation of force imaging at the atomic scale on alkali halide crystals. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:4915-4930. [PMID: 10011425 DOI: 10.1103/physrevb.49.4915] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Kantorovich L, Heifets E, Livshicz A, Kuklja M, Zapol P. Theoretical analysis of hole self-trapping in ionic solids: Application to the KCl crystal. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:14875-14885. [PMID: 10005862 DOI: 10.1103/physrevb.47.14875] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Shluger AL, Itoh N, Puchin VE, Heifets EN. Two types of self-trapped excitons in alkali halide crystals. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:1499-1508. [PMID: 9999683 DOI: 10.1103/physrevb.44.1499] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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