1
|
Khattab ESR, Abd El Rehim SS, Hassan WMI, El-Shazly TS. Band Structure Engineering and Optical Properties of Pristine and Doped Monoclinic Zirconia ( m-ZrO 2): Density Functional Theory Theoretical Prospective. ACS OMEGA 2021; 6:30061-30068. [PMID: 34778677 PMCID: PMC8582270 DOI: 10.1021/acsomega.1c04756] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
Recently, monoclinic ZrO2 has received great technological importance because of its remarkable dielectric properties, high chemical stability, and high melting point. Herein, we introduce first-principles calculations using the Hubbard approach (DFT + U) to study the effects of doping with Nb and W on the electronic and optical properties of pristine ZrO2. The introduction of dopant atoms into the pristine crystal structure led to the displacement of the bandgap edges and reallocation of the Fermi level. The valence band maximum (VBM) shifted upward, resulting in band gap tightening from 5.79 to 0.89 for ZrO2: Nb and to 1.33 eV for ZrO2: W. The optical absorption of doped crystals extended into the visible and near-infrared regions. Partial density of states (PDOS) calculations showed valence band dependency on the O 2p orbital energy, with the conduction band predominantly composed of Nb 4d and W 5d. For pristine ZrO2, the results obtained for the imaginary and real parts of the dielectric function, the refractive index, and the reflectivity show good agreement with the available experimental and theoretical results. For ZrO2:W, we checked the dopant location effect, and the obtained results showed no significant effect on the calculated values of the band gap with a maximum difference of 0.17 eV. Significant band gap tightening and optical properties of our systems indicate that these systems could be promising candidates for photoelectrochemical energy conversion (PEC) applications.
Collapse
Affiliation(s)
- El-Sayed R. Khattab
- Department
of Chemistry, Faculty of Science, Ain-Shams
University, Cairo 11566, Egypt
| | - Sayed S. Abd El Rehim
- Department
of Chemistry, Faculty of Science, Ain-Shams
University, Cairo 11566, Egypt
| | - Walid M. I. Hassan
- Department
of Chemistry, Faculty of Science, Cairo
University, Giza 12613, Egypt
| | - Tamer S. El-Shazly
- Department
of Chemistry, Faculty of Science, Ain-Shams
University, Cairo 11566, Egypt
| |
Collapse
|
2
|
Zhang Y. Fe(phen) 2(NCS) 2 on Al(100): influence of AlN layer on spin crossover barrier. Phys Chem Chem Phys 2021; 23:23758-23767. [PMID: 34643204 DOI: 10.1039/d1cp03782j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We study how a nitride layer affects spin crossover (SCO) in a single Fe(phen)2(NCS)2 (Fephen) molecule adsorbed on the Al(100) surface using ab initio calculations. The Coulomb correlation of the open-shell 3d electrons has been considered using a Hubbard-U correction within different exchange-correlation approximations, including the van der Waals density functional. We determine the SCO energy barrier by computing the minimum energy path between the high-spin (HS) and low-spin (LS) states via direct constraint relaxations. It is shown that the HS-LS energy difference is slightly increased once deposited on Al(100), and thus LS states tend to be stabilized, as usually observed on metallic substrates. The oxidation of metallic Al to aluminum ions in the AlN layer promotes molecular adsorption, while it decreases HS-LS splitting, making Fephen switchable between its two spin states. Due to enhanced molecule-substrate bonding, the SCO barrier height is considerably increased, which may promote cooperativity. This effect is consistent with the AlN facilitated charge transfer at the interface that results from a reduction in surface work function. Our findings reveal the crucial role that surface electronic structure plays in maintaining spin bistability of the molecular adsorbate.
Collapse
Affiliation(s)
- Yachao Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, China.
| |
Collapse
|
3
|
Mariano LA, Vlaisavljevich B, Poloni R. Biased Spin-State Energetics of Fe(II) Molecular Complexes within Density-Functional Theory and the Linear-Response Hubbard U Correction. J Chem Theory Comput 2020; 16:6755-6762. [DOI: 10.1021/acs.jctc.0c00628] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Lorenzo A. Mariano
- Grenoble-INP, SIMaP, University of Grenoble-Alpes, CNRS, F-38042 Grenoble, France
| | - Bess Vlaisavljevich
- Department of Chemistry, University of South Dakota, Vermillion, South Dakota 57069, United States
| | - Roberta Poloni
- Grenoble-INP, SIMaP, University of Grenoble-Alpes, CNRS, F-38042 Grenoble, France
| |
Collapse
|
4
|
Zhang Y. Surface effects on temperature-driven spin crossover in Fe(phen) 2(NCS) 2. J Chem Phys 2020; 153:134704. [DOI: 10.1063/5.0027641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yachao Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, China
| |
Collapse
|
5
|
Zhang M, Cui Z, Wang Y, Jiang H. Hybrid functionals with system‐dependent parameters: Conceptual foundations and methodological developments. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2020. [DOI: 10.1002/wcms.1476] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Min‐Ye Zhang
- Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering, Peking University Beijing China
| | - Zhi‐Hao Cui
- Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena California USA
| | - Yue‐Chao Wang
- Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering, Peking University Beijing China
| | - Hong Jiang
- Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering, Peking University Beijing China
| |
Collapse
|
6
|
Zhang Y. Calculating spin crossover temperatures by a first-principles LDA+U scheme with parameter U evaluated from GW. J Chem Phys 2019; 151:134701. [PMID: 31594359 DOI: 10.1063/1.5124239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The prediction of spin crossover (SCO) temperatures (T1/2) depends sensitively on the description of local Coulomb correlation. Due to its balance between accuracy and computational cost, local density approximation combined with Hubbard U model (LDA+U) is an appealing tool for this purpose. Despite its accurate performance on energetic properties, such as spin adiabatic energy difference, it is well-known that the LDA+U approach would lose its predictive power if U is tuned to achieve close agreement with experiment for a certain property. On the other hand, a static U value cannot account for changes in the electronic structure. Here, we propose a framework to derive dynamical U (Udyn) values for iron(ii) complexes from the many-body GW calculations. By performing model calculations on a series of compounds with varying ligand fields, we show that the U values determined in this way are local environment dependent, and the resulting LDA+Udyn method could reproduce their experimental ground spin states. We present applications to selected SCO complexes illustrating that Udyn considerably overcomes some of the drawbacks of employing a constant U in the calculation of thermochemical quantities. Using the described calculation procedure, the T1/2 values are predicted with a small mean absolute error of 176 K with respect to experiment.
Collapse
Affiliation(s)
- Yachao Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, China
| |
Collapse
|
7
|
Wang YC, Jiang H. Local screened Coulomb correction approach to strongly correlated d-electron systems. J Chem Phys 2019; 150:154116. [DOI: 10.1063/1.5089464] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Yue-Chao Wang
- Beijing National Laboratory for Molecular Sciences, Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Hong Jiang
- Beijing National Laboratory for Molecular Sciences, Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
8
|
David G, Wennmohs F, Neese F, Ferré N. Chemical Tuning of Magnetic Exchange Couplings Using Broken-Symmetry Density Functional Theory. Inorg Chem 2018; 57:12769-12776. [DOI: 10.1021/acs.inorgchem.8b01970] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Frank Wennmohs
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470 North Rhine-Westphalia, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470 North Rhine-Westphalia, Germany
| | | |
Collapse
|
9
|
Zhang Y. Driving spin transition at interface: Role of adsorption configurations. J Chem Phys 2018; 148:044706. [PMID: 29390826 DOI: 10.1063/1.5007739] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A clear insight into the electrical manipulation of molecular spins at interface is crucial to the design of molecule-based spintronic devices. Here we report on the electrically driven spin transition in manganocene physisorbed on a metallic surface in two different adsorption configurations predicted by ab initio techniques, including a Hubbard-U correction at the manganese site and accounting for the long-range van der Waals interactions. We show that the application of an electric field at the interface induces a high-spin to low-spin transition in the flat-lying manganocene, while it could hardly alter the high-spin ground state of the standing-up molecule. This phenomenon cannot be explained by either the molecule-metal charge transfer or the local electron correlation effects. We demonstrate a linear dependence of the intra-molecular spin-state splitting on the energy difference between crystal-field splitting and on-site Coulomb repulsion. After considering the molecule-surface binding energy shifts upon spin transition, we reproduce the obtained spin-state energetics. We find that the configuration-dependent responses of the spin-transition originate from the binding energy shifts instead of the variation of the local ligand field. Through these analyses, we obtain an intuitive understanding of the effects of molecule-surface contact on spin-crossover under electrical bias.
Collapse
Affiliation(s)
- Yachao Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, China
| |
Collapse
|
10
|
Hao H, Jia T, Zheng X, Zeng Z. Bias induced spin transitions of spin crossover molecules: the role of charging effect. Phys Chem Chem Phys 2017; 19:7652-7658. [PMID: 28256678 DOI: 10.1039/c6cp08265c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The spin transition of spin crossover molecules induced by bias voltages from low spin to high spin was observed recently and several mechanisms were suggested to understand it. However, these mechanisms fail to explain the dependence of spin transitions on the bias polarity in experiments and thus may still be questionable. Based on a first-principles study, we propose that the bias-induced spin transition is triggered by a charging effect, namely, the filling of the lowest unoccupied molecular orbital of spin crossover molecules. Our proposal is substantiated by three steps: (1) the spin transition from low spin to high spin can be achieved by charging the isolated spin crossover molecules with one extra electron; (2) in molecular junctions, the charging of spin crossover molecules can be realized by electron transfer from electrodes to molecules under finite bias; (3) more importantly, the electron transfer is dependent on the bias polarity due to asymmetrical couplings of the sandwiched molecule with two electrodes. This mechanism satisfactorily explains the bias-polarity dependent spin transitions in experiments [Miyamachi et al., Nat. Commun., 2012, 3, 938; Gopakumar et al., Angew. Chem. Int. Ed., 2012, 51, 6262].
Collapse
Affiliation(s)
- Hua Hao
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. and University of Science and Technology of China, Hefei, 230026, China
| | - Ting Jia
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. and University of Science and Technology of China, Hefei, 230026, China
| | - Xiaohong Zheng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. and University of Science and Technology of China, Hefei, 230026, China
| | - Zhi Zeng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. and University of Science and Technology of China, Hefei, 230026, China and Beijing Computational Science Research Center, Beijing 100084, China
| |
Collapse
|
11
|
Zhang Y. Molecular spin on surface: From strong correlation to dispersion interactions. J Chem Phys 2016; 145:124704. [DOI: 10.1063/1.4963338] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yachao Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, China
| |
Collapse
|
12
|
Zhang Y. Predicting critical temperatures of iron(II) spin crossover materials: Density functional theory plus U approach. J Chem Phys 2014; 141:214703. [DOI: 10.1063/1.4902542] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
13
|
Houghton BJ, Deeth RJ. Spin-State Energetics of FeIIComplexes - The Continuing Voyage Through the Density Functional Minefield. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402253] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
14
|
Rudavskyi A, Sousa C, de Graaf C, Havenith RWA, Broer R. Computational approach to the study of thermal spin crossover phenomena. J Chem Phys 2014; 140:184318. [DOI: 10.1063/1.4875695] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
15
|
Zhang Y, Yang Y, Jiang H. 3d–4f Magnetic Interaction with Density Functional Theory Plus U Approach: Local Coulomb Correlation and Exchange Pathways. J Phys Chem A 2013; 117:13194-204. [DOI: 10.1021/jp4103228] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Yachao Zhang
- Beijing
National Laboratory
of Molecular Sciences, State Key Laboratory of Rare Earth Materials
Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yang Yang
- Beijing
National Laboratory
of Molecular Sciences, State Key Laboratory of Rare Earth Materials
Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Hong Jiang
- Beijing
National Laboratory
of Molecular Sciences, State Key Laboratory of Rare Earth Materials
Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
16
|
Rudavskyi A, Havenith RWA, Broer R, de Graaf C, Sousa C. Explanation of the site-specific spin crossover in Fe(mtz)6(BF4)2. Dalton Trans 2013; 42:14702-9. [DOI: 10.1039/c3dt52027g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
17
|
Ali ME, Nair NN, Staemmler V, Marx D. Constrained spin-density dynamics of an iron-sulfur complex: Ferredoxin cofactor. J Chem Phys 2012; 136:224101. [DOI: 10.1063/1.4722552] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
18
|
Rokob TA, Srnec M, Rulíšek L. Theoretical calculations of physico-chemical and spectroscopic properties of bioinorganic systems: current limits and perspectives. Dalton Trans 2012; 41:5754-68. [DOI: 10.1039/c2dt12423h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|