1
|
Materzanini G, Chiarotti T, Marzari N. Solids that are also liquids: elastic tensors of superionic materials. NPJ COMPUTATIONAL MATERIALS 2023; 9:10. [PMID: 38666054 PMCID: PMC11041723 DOI: 10.1038/s41524-022-00948-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 12/10/2022] [Indexed: 04/28/2024]
Abstract
Superionics are fascinating materials displaying both solid- and liquid-like characteristics: as solids, they respond elastically to shear stress; as liquids, they display fast-ion diffusion at normal conditions. In addition to such scientific interest, superionics are technologically relevant for energy, electronics, and sensing applications. Characterizing and understanding their elastic properties is, e.g., urgently needed to address their feasibility as solid-state electrolytes in all-solid-state batteries. However, static approaches to elasticity assume well-defined reference positions around which atoms vibrate, in contrast with the quasi-liquid motion of the mobile ions in fast ionic conductors. Here, we derive the elastic tensors of superionics from ensemble fluctuations in the isobaric-isothermal ensemble, exploiting extensive Car-Parrinello simulations. We apply this approach to paradigmatic Li-ion conductors, and complement with a block analysis to compute statistical errors. Static approaches sampled over the trajectories often overestimate the response, highlighting the importance of a dynamical treatment in determining elastic tensors in superionics.
Collapse
Affiliation(s)
- Giuliana Materzanini
- Theory and Simulations of Materials (THEOS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Present Address: Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Tommaso Chiarotti
- Theory and Simulations of Materials (THEOS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Nicola Marzari
- Theory and Simulations of Materials (THEOS), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| |
Collapse
|
2
|
Finkler JA, Goedecker S. Experimental absence of the non-perovskite ground state phases of MaPbI 3 explained by a Funnel Hopping Monte Carlo study based on a neural network potential. MATERIALS ADVANCES 2023; 4:184-194. [PMID: 36685989 PMCID: PMC9812259 DOI: 10.1039/d2ma00958g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
Methylammonium lead iodide is a material known for its exceptional opto-electronic properties that make it a promising candidate for many high performance applications, such as light emitting diodes or solar cells. A recent computational structure search revealed two previously unknown non-perovskite polymorphs, that are lower in energy than the experimentally observed perovskite phases. To investigate the elusiveness of the non-perovskite phases in experimental studies, we extended our Funnel Hopping Monte Carlo (FHMC) method to periodic systems and performed extensive MC simulations driven by a machine learned potential. FHMC simulations that also include these newly discovered non-perovskite phases show that above temperatures of 200 K the perovskite phases are thermodynamically preferred. A comparison with the quasi-harmonic approximation highlights the importance of anharmonic effects captured by FHMC.
Collapse
Affiliation(s)
- Jonas A Finkler
- Department of Physics, University of Basel Klingelbergstrasse 82 4056 Basel Switzerland
| | - Stefan Goedecker
- Department of Physics, University of Basel Klingelbergstrasse 82 4056 Basel Switzerland
| |
Collapse
|
3
|
Shu Z, Cui X, Wang B, Yan H, Cai Y. Fast Intercalation of Lithium in Semi-Metallic γ-GeSe Nanosheet: A New Group-IV Monochalcogenide for Lithium-Ion Battery Application. CHEMSUSCHEM 2022; 15:e202200564. [PMID: 35680606 DOI: 10.1002/cssc.202200564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/12/2022] [Indexed: 06/15/2023]
Abstract
Existence of van der Waals gaps renders two-dimensional (2D) materials ideal passages of lithium for being used as anode materials. However, the requirement of good conductivity significantly limits the choice of 2D candidates. So far, only graphite is satisfying due to its relatively high conductivity. Recently, a new polymorph of layered germanium selenide (γ-GeSe) was proven to be semimetal in its bulk phase with a higher conductivity than graphite while its monolayer behaves semiconducting. In this work, by using first-principles calculations, the possibility was investigated of using this new group-IV monochalcogenide, γ-GeSe, as anode in Li-ion batteries (LIBs). The studies revealed that the Li atom would form an ionic adsorption with adjacent selenium atoms at the hollow site and exist in cationic state (lost 0.89 e to γ-GeSe). Results of climbing image-nudged elastic band showed the diffusion barrier of Li was 0.21 eV in the monolayer limit, which could activate a relatively fast diffusion even at room temperature on the γ-GeSe surface. The calculated theoretical average voltages ranged from 0.071 to 0.015 V at different stoichiometry of Lix GeSe with minor volume variation, suggesting its potential application as anode of LIBs. The predicted moderate binding energy, a low open-circuit voltage (comparable to graphite), and a fast motion of Li suggested that γ-GeSe nanosheet could be chemically exfoliated via Li intercalation and is a promising candidate as the anode material for LIBs.
Collapse
Affiliation(s)
- Zheng Shu
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, China
| | - Xiangyue Cui
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, China
| | - Bowen Wang
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, China
| | - Hejin Yan
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, China
| | - Yongqing Cai
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, China
| |
Collapse
|
4
|
Liu S, Gao P, Hermann A, Yang G, Lü J, Ma Y, Mao HK, Wang Y. Stabilization of S 3O 4 at high pressure: implications for the sulfur-excess paradox. Sci Bull (Beijing) 2022; 67:971-976. [PMID: 36546032 DOI: 10.1016/j.scib.2022.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/19/2021] [Accepted: 12/20/2021] [Indexed: 01/06/2023]
Abstract
The amount of sulfur in SO2 discharged in volcanic eruptions exceeds that available for degassing from the erupted magma. This geological conundrum, known as the "sulfur excess", has been the subject of considerable interests but remains an open question. Here, in a systematic computational investigation of sulfur-oxygen compounds under pressure, a hitherto unknown S3O4 compound containing a mixture of sulfur oxidation states +II and +IV is predicted to be stable at pressures above 79 GPa. We speculate that S3O4 may be produced via redox reactions involving subducted S-bearing minerals (e.g., sulfates and sulfides) with iron and goethite under high-pressure conditions of the deep lower mantle, decomposing to SO2 and S at shallow depths. S3O4 may thus be a key intermediate in promoting decomposition of sulfates to release SO2, offering an alternative source of excess sulfur released during explosive eruptions. These findings provide a possible resolution of the "excess sulfur degassing" paradox and a viable mechanism for the exchange of S between Earth's surface and the lower mantle in the deep sulfur cycle.
Collapse
Affiliation(s)
- Siyu Liu
- State Key Laboratory of Superhard Materials & International Center of Computational Method and Software, College of Physics, Jilin University, Changchun 130012, China
| | - Pengyue Gao
- State Key Laboratory of Superhard Materials & International Center of Computational Method and Software, College of Physics, Jilin University, Changchun 130012, China
| | - Andreas Hermann
- Centre for Science at Extreme Conditions and Scottish Universities Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3FD, UK
| | - Guochun Yang
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
| | - Jian Lü
- State Key Laboratory of Superhard Materials & International Center of Computational Method and Software, College of Physics, Jilin University, Changchun 130012, China.
| | - Yanming Ma
- State Key Laboratory of Superhard Materials & International Center of Computational Method and Software, College of Physics, Jilin University, Changchun 130012, China; International Center of Future Science, Jilin University, Changchun 130012, China
| | - Ho-Kwang Mao
- Center for High Pressure Science and Technology Advanced Research, Beijing 100094, China.
| | - Yanchao Wang
- State Key Laboratory of Superhard Materials & International Center of Computational Method and Software, College of Physics, Jilin University, Changchun 130012, China.
| |
Collapse
|
5
|
Wang C, Chang D, Wang J, Gao Q, Zhang Y, Niu C, Liu C, Jia Y. Size and crystal symmetry breaking effects on negative thermal expansion in ScF 3 nanostructures. Phys Chem Chem Phys 2021; 23:24814-24822. [PMID: 34714310 DOI: 10.1039/d1cp02809j] [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
Nowadays, one of the most typical and important potential applications of negative thermal expansion (NTE) materials is to prepare zero thermal expansion or controllable coefficient thermal expansion materials by compounding them with positive thermal expansion materials. The research on NTE properties at the nanoscales is the basis and premise for the realization of high-quality composites. Here, using first-principles calculations, we take a typical open framework material ScF3 as an example to study a new NTE mechanism at the nanoscale, which involves edge and size effects, as well as crystal symmetry breaking. By analyzing the vibrational modes in ultrathin ScF3 films, three effects contributing to the NTE properties are identified, namely, the acoustic mode (ZA mode) induced by surface truncation, the enhanced rotations of ScF6 octahedra in the surface layer and the suppressed rotations of ScF6 octahedra in the inner layer due to crystal symmetry breaking. With increasing thickness, the effect of the ZA mode vibration gradually weakens, while the rotations of the ScF6 octahedra in the surface and inner layers are enhanced. Ultimately, the approximately mutual compensation of these three effects makes the NTE coefficients of different thicknesses almost unchanged. Finally, we simply generalize our conclusions to zero dimensional nanoparticles. This work reveals a new NTE mechanism in low-dimensional open framework materials, which serves as a guide in designing NTE materials at the nanoscale.
Collapse
Affiliation(s)
- Chunyan Wang
- International Laboratory for Quantum Functional Materials of Henan, and School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China.,Key Laboratory for Special Functional Materials of Ministry of Education, and School of Materials and Engineering, Henan University, Kaifeng 475001, China
| | - Dahu Chang
- Department of Mathematics and Physics, Luoyang Institute of Science and Technology, Luoyang 471023, China
| | - Junfei Wang
- College of Science, Henan University of Technology, Zhengzhou 450001, China
| | - Qilong Gao
- International Laboratory for Quantum Functional Materials of Henan, and School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China
| | - Yinuo Zhang
- International Laboratory for Quantum Functional Materials of Henan, and School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China
| | - Chunyao Niu
- International Laboratory for Quantum Functional Materials of Henan, and School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China
| | - Chengyan Liu
- Key Laboratory for Special Functional Materials of Ministry of Education, and School of Materials and Engineering, Henan University, Kaifeng 475001, China
| | - Yu Jia
- International Laboratory for Quantum Functional Materials of Henan, and School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China.,Key Laboratory for Special Functional Materials of Ministry of Education, and School of Materials and Engineering, Henan University, Kaifeng 475001, China
| |
Collapse
|
6
|
Morresi T, Paulatto L, Vuilleumier R, Casula M. Probing anharmonic phonons by quantum correlators: A path integral approach. J Chem Phys 2021; 154:224108. [PMID: 34241203 DOI: 10.1063/5.0050450] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We devise an efficient scheme to determine vibrational properties from Path Integral Molecular Dynamics (PIMD) simulations. The method is based on zero-time Kubo-transformed correlation functions and captures the anharmonicity of the potential due to both temperature and quantum effects. Using analytical derivations and numerical calculations on toy-model potentials, we show that two different estimators built upon PIMD correlation functions fully characterize the phonon spectra and the anharmonicity strength. The first estimator is associated with the force-force quantum correlators and, in the weak anharmonic regime, yields reliable zero-point motion frequencies and thermodynamic properties of the quantum system. The second one is instead connected to displacement-displacement correlators and accurately probes the lowest-energy phonon excitations, regardless of the anharmonicity strength of the system. We also prove that the use of generalized eigenvalue equations, in place of the standard normal mode equations, leads to a significant speed-up in the PIMD phonon calculations, both in terms of faster convergence rate and smaller time step bias. Within this framework, using ab initio PIMD simulations, we compute phonon dispersions of diamond and of the high-pressure I41/amd phase of atomic hydrogen. We find that in the latter case, the anharmonicity is stronger than previously estimated and yields a sizeable red-shift in the vibrational spectrum of atomic hydrogen.
Collapse
Affiliation(s)
- T Morresi
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, CNRS UMR 7590, MNHN, 4 Place Jussieu, 75252 Paris, France
| | - L Paulatto
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, CNRS UMR 7590, MNHN, 4 Place Jussieu, 75252 Paris, France
| | - R Vuilleumier
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - M Casula
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, CNRS UMR 7590, MNHN, 4 Place Jussieu, 75252 Paris, France
| |
Collapse
|
7
|
Keshri SP, Medhi A. Enhanced thermoelectric efficiency of monolayer InP 3under strain: a first-principles study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:225701. [PMID: 33601361 DOI: 10.1088/1361-648x/abe799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Abstract
We study the thermoelectric properties of monolayer indium triphosphide (InP3) under uniaxial compressive and tensile strains using density functional theory in conjunction with Boltzmann transport formalism. InP3is a recently predicted two-dimensional (2D) material with a host of interesting multi-functional properties. Though InP3is a low lattice thermal conductivity material, its thermoelectric figure of merit,ZTis found to be low. We thoroughly examined how its thermoelectric transport properties evolve under external strain. We find that the tensile (t) and compressive (c) strains have contrasting effects on the transport coefficients, both leading to the same effect of enhancing theZTvalue strongly. Whilet-strain enhances the power factor dramatically,c-strain gives rise to an ultra-low lattice thermal conductivity. Both these effects lead to an enhancement ofZTvalue at high temperatures by an order of magnitude compared to the corresponding value for free InP3. The maximumZTvalue of InP3at 800 K is found to be ∼0.4 undert-strain and ∼0.32 underc-strain, values which are comparable to those observed for some of the leading 2D thermoelectric materials. Another finding relevant to optoelectronic properties is that underc-strain the material shows a transition from an indirect to a direct band gap semiconductor with an accompanying increase in the valley degeneracy. The structural, electronic, and thermal properties of the material are thoroughly analyzed and discussed.
Collapse
Affiliation(s)
- Sonu Prasad Keshri
- Indian Institute of Science Education and Research Thiruvananthapuram, Kerala 695551, India
| | - Amal Medhi
- Indian Institute of Science Education and Research Thiruvananthapuram, Kerala 695551, India
| |
Collapse
|
8
|
Shi L, Ma X, Li M, Zhong Y, Yang L, Yin W, He X. Molecular dynamics simulation of phonon thermal transport in nanotwinned diamond with a new optimized Tersoff potential. Phys Chem Chem Phys 2021; 23:8336-8343. [PMID: 33875998 DOI: 10.1039/d1cp00399b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The inaccuracy of the most widely used potentials in calculating the phonon transport of sp3 carbon materials hinders the use of molecular dynamics simulations for revealing the underlying mechanism of phonon transport in diamond and related materials. Here, we introduce an optimized Tersoff potential by optimizing the parameters to fit the experimentally determined phonon dispersion in diamond along the high-symmetry directions. Molecular dynamics simulations are performed using this new potential to investigate the phonon thermal transport in flawless and nanotwinned diamond. The simulation results show that while the phonon lifetimes of nanotwinned diamond are slightly lower than those of the flawless one, the phonon group velocities of nanotwinned diamond are obviously lower than those of diamond. The present results indicate that the twin boundaries in diamond are ineffective in scattering the phonons and the lower thermal conductivity of the nanotwinned diamond mainly originates from the lower group velocities due to its reduced structural rigidity.
Collapse
Affiliation(s)
- Liping Shi
- Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, China.
| | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
The physical properties of molecular crystals are governed by the frontier orbitals of molecules. A molecular orbital, which is formed by superposing the atomic orbitals of constituent elements, has complicated degrees of freedom in the crystal because of the influence of electron correlation and crystal field. Therefore, in general, it is difficult to experimentally observe the whole picture of a frontier orbital. Here, we introduce a new method called “core differential Fourier synthesis” (CDFS) using synchrotron X-ray diffraction to observe the valence electron density in materials. By observing the valence electrons occupied in molecular orbitals, the orbital state can be directly determined in a real space. In this study, we applied the CDFS method to molecular materials such as diamond, C60 fullerene, (MV)I2, and (TMTTF)2X. Our results not only demonstrate the typical orbital states in some materials, but also provide a new method for studying intramolecular degrees of freedom.
Collapse
|
10
|
Luo Z, Liu L, Yang X, Luo X, Bi P, Fu Z, Pang A, Li W, Yi Y. Revealing the Charge Storage Mechanism of Nickel Oxide Electrochromic Supercapacitors. ACS APPLIED MATERIALS & INTERFACES 2020; 12:39098-39107. [PMID: 32805941 DOI: 10.1021/acsami.0c09606] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nickel oxide (NiO) is considered one of the most promising positive anode materials for electrochromic supercapacitors. Nevertheless, a detailed mechanism of the electrochromic and energy storage process has yet to be unraveled. In this research, the charge storage mechanism of a NiO electrochromic electrode was investigated by combining the in-depth experimental and theoretical analyses. Experimentally, a kinetic analysis of the Li-ion behavior based on the cyclic voltammetry curves reveals the major contribution of surface capacitance versus total capacity, providing fast reaction kinetics and a highly reversible electrochromic performance. Theoretically, our model uncovers that Li ions prefer to adsorb at fcc sites on the NiO(1 1 1) surface, then diffuse horizontally over the plane, and finally migrate in the bulk. More significantly, the calculated theoretical surface capacity (106 mA h g-1) accounts for about 77.4% of the total experimental capacity (137 mA h g-1), indicating that the surface storage process dominates the whole charge storage, which is in accordance with the experimental results. This work provides a fundamental understanding of transition-metal oxides for application in electrochromic supercapacitors and can also promote the exploration of novel electrode materials for high-performance electrochromic supercapacitors.
Collapse
Affiliation(s)
- Zhihui Luo
- State Key Laboratory for Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China
| | - Lei Liu
- School of Physics, Beihang University, Beijing 100191, China
| | - Xiaoyong Yang
- State Key Laboratory for Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Upsala University, Uppsala 75120, Sweden
| | - Xuan Luo
- Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
| | - Peng Bi
- School of Science, Southwest University of Science and Technology, Mianyang 621010, China
| | - Zhenjin Fu
- State Key Laboratory for Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China
| | - Aimin Pang
- Science and Technology on Aerospace Chemical Power Laboratory, Hubei Institute of Aerospace Chemotechnology, Xiangyang 441003, Hubei, China
| | - Wei Li
- Science and Technology on Aerospace Chemical Power Laboratory, Hubei Institute of Aerospace Chemotechnology, Xiangyang 441003, Hubei, China
| | - Yong Yi
- State Key Laboratory for Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China
| |
Collapse
|
11
|
Kumar V, Di Stefano D, Rignanese GM, Gonze X. Li diffusion in Si and LiSi: Nuclear quantum effects and anharmonicity. J Chem Phys 2020; 152:244101. [PMID: 32610994 DOI: 10.1063/5.0007648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The diffusion of Li in bulk Si and crystalline LiSi is investigated over a wide range of temperatures employing first-principles calculations based on density functional theory, transition state theory, and the kinetic Monte Carlo method. Nuclear quantum effects are incorporated by computing the vibrational spectrum and its effect on the effective energy barrier. The Li diffusion coefficient in bulk Si calculated with such quantum effects is ∼33% lower than the classical limit near room temperature due to higher effective energy barrier and tends to the classical limit at a high temperature (>1000 K). The presence of anharmonicity, estimated by the quasiharmonic approximation and the cBΩ model, increases the diffusion coefficient by ∼60%. For Li diffusion in LiSi with multiple vacancy jumps, we obtain an effective diffusion barrier of 0.27 eV ± 0.01 eV. In the Li-Si system, the quantum mechanical effects are only marginally significant at room temperature.
Collapse
Affiliation(s)
- Vishank Kumar
- Institute for Condensed Matter and Nanosciences, European Theoretical Spectroscopy Facility, Université Catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - Davide Di Stefano
- Institute for Condensed Matter and Nanosciences, European Theoretical Spectroscopy Facility, Université Catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - Gian-Marco Rignanese
- Institute for Condensed Matter and Nanosciences, European Theoretical Spectroscopy Facility, Université Catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - Xavier Gonze
- Institute for Condensed Matter and Nanosciences, European Theoretical Spectroscopy Facility, Université Catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| |
Collapse
|
12
|
Shiryaev AA, Polyakov VB, Rols S, Rivera A, Shenderova O. Inelastic neutron scattering: a novel approach towards determination of equilibrium isotopic fractionation factors. Size effects on heat capacity and beta-factor of diamond. Phys Chem Chem Phys 2020; 22:13261-13270. [PMID: 32500891 DOI: 10.1039/d0cp02032j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new experimental method for the determination of equilibrium isotopic properties of substances based on inelastic neutron scattering (INS) is proposed. We present a mathematical formalism, which allows the calculation of the beta-factor of single-element solids based on INS-derived Phonon Density of States (PDOS). PDOS data for nanodiamonds of widely different sizes and of macroscopic diamond were determined from inelastic neutron scattering experiments. This allowed the determination of heat capacities and, for the first time, β-factors of the diamond nanoparticles. We demonstrate a considerable size-dependent increase of the heat capacities and decrease of the beta-factors for nanodiamonds relative to bulk diamond. Contributions of surface impurities/phases and phonon confinement to the size effects are evaluated. Applications in the formation of diamond nanoparticles in nature are briefly discussed.
Collapse
Affiliation(s)
- Andrey A Shiryaev
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry RAS, Leninsky pr. 31 korp. 4, 119071, Moscow, Russia.
| | | | | | | | | |
Collapse
|
13
|
Granada JR, Márquez Damián JI, Helman C. Studies on Reflector Materials for Cold Neutrons. EPJ WEB OF CONFERENCES 2020. [DOI: 10.1051/epjconf/202023104002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Neutron scattering techniques and neutron applications in general are powerful and well-established tools for research in science and technology. However, those are highly intensity-limited techniques and the need to reduce the neutron loses between their source to detection is then an imperative endeavor. In particular, great effort has been devoted to the development of efficient ways to transport and guide neutron beams, as well as to reduce the flux leakage in the non-emitting sides of moderator systems. In this work we investigate and confirm by calculation in a real material the great quality of diamond nanoparticles as reflector for ultra-cold and very-cold neutrons, and propose the use of Magnesium Hydride at a low temperature as a very good reflector for cold neutrons
Collapse
|
14
|
Hu X, Hemmat Z, Majidi L, Cavin J, Mishra R, Salehi-Khojin A, Ogut S, Klie RF. Controlling Nanoscale Thermal Expansion of Monolayer Transition Metal Dichalcogenides by Alloy Engineering. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1905892. [PMID: 31830372 DOI: 10.1002/smll.201905892] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/19/2019] [Indexed: 06/10/2023]
Abstract
2D materials, such as transition metal dichalcogenides (TMDs), graphene, and boron nitride, are seen as promising materials for future high power/high frequency electronics. However, the large difference in the thermal expansion coefficient (TEC) between many of these 2D materials could impose a serious challenge for the design of monolayer-material-based nanodevices. To address this challenge, alloy engineering of TMDs is used to tailor their TECs. Here, in situ heating experiments in a scanning transmission electron microscope are combined with electron energy-loss spectroscopy and first-principles modeling of monolayer Mo1- x Wx S2 with different alloying concentrations to determine the TEC. Significant changes in the TEC are seen as a function of chemical composition in Mo1- x Wx S2 , with the smallest TEC being reported for a configuration with the highest entropy. This study provides key insights into understanding the nanoscale phenomena that control TEC values of 2D materials.
Collapse
Affiliation(s)
- Xuan Hu
- Department of Physics, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Zahra Hemmat
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Leily Majidi
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - John Cavin
- Department of Physics, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Rohan Mishra
- Department of Mechanical Engineering and Materials Science and Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Amin Salehi-Khojin
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Serdar Ogut
- Department of Physics, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Robert F Klie
- Department of Physics, University of Illinois at Chicago, Chicago, IL, 60607, USA
| |
Collapse
|
15
|
Tristant D, Cupo A, Ling X, Meunier V. Phonon Anharmonicity in Few-Layer Black Phosphorus. ACS NANO 2019; 13:10456-10468. [PMID: 31436958 DOI: 10.1021/acsnano.9b04257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report a temperature-dependent Raman spectroscopy study of few-layer black phosphorus (BP) with varied incident polarization and sample thickness. The Raman-active modes Ag1, B2g, and Ag2 exhibit a frequency downshift, while their line width tends to increase with increasing temperature. To understand the details of these phenomena, we perform first-principles density functional theory calculations on freestanding monolayer BP. The effect of thermal expansion is included by constraining the temperature-dependent lattice constant. The study of the temperature-induced shift of the phonon frequencies is carried out using ab initio molecular dynamics simulations. The normal-mode frequencies are calculated by identifying the peak positions from the magnitude of the Fourier transform of the total velocity autocorrelation. Anharmonicity induces a frequency shift for each individual mode, and the three- and four-phonon process coefficients are extracted. These results are compared with those obtained from many-body perturbation theory, giving access to phonon lifetimes and lattice thermal conductivity. We establish that the frequency downshift is primarily due to phonon-phonon scattering while thermal expansion only contributes indirectly by renormalizing the phonon-phonon scattering. Overall, the theoretical results are in excellent agreement with experiment, thus showing that controlling phonon scattering in BP could result in better thermoelectric devices or transistors that dissipate heat more effectively when confined to the nanoscale.
Collapse
Affiliation(s)
- Damien Tristant
- Department of Physics, Applied Physics, and Astronomy , Rensselaer Polytechnic Institute , Troy , New York 12180 , United States
| | - Andrew Cupo
- Department of Physics, Applied Physics, and Astronomy , Rensselaer Polytechnic Institute , Troy , New York 12180 , United States
| | - Xi Ling
- Department of Chemistry, Division of Materials Science and Engineering, and The Photonics Center , Boston University , Boston , Massachusetts 02215 , United States
| | - Vincent Meunier
- Department of Physics, Applied Physics, and Astronomy , Rensselaer Polytechnic Institute , Troy , New York 12180 , United States
| |
Collapse
|
16
|
Dampf SJ, Korter TM. Anomalous Temperature Dependence of the Lowest-Frequency Lattice Vibration in Crystalline γ-Aminobutyric Acid. J Phys Chem A 2019; 123:2058-2064. [DOI: 10.1021/acs.jpca.8b12572] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sara J. Dampf
- Department of Chemistry, Syracuse University, 1-014 Center for Science and Technology, Syracuse, New York 13244-4100, United States
| | - Timothy M. Korter
- Department of Chemistry, Syracuse University, 1-014 Center for Science and Technology, Syracuse, New York 13244-4100, United States
| |
Collapse
|
17
|
Pang J, Tao L, Lu X, Yang Q, Pachauri V, Wang Z, Ingebrandt S, Chen X. Photothermal effects induced by surface plasmon resonance at graphene/gold nanointerfaces: A multiscale modeling study. Biosens Bioelectron 2019; 126:470-477. [DOI: 10.1016/j.bios.2018.11.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 10/27/2018] [Accepted: 11/04/2018] [Indexed: 01/03/2023]
|
18
|
Jena NK, Araujo RB, Shukla V, Ahuja R. Borophane as a Benchmate of Graphene: A Potential 2D Material for Anode of Li and Na-Ion Batteries. ACS APPLIED MATERIALS & INTERFACES 2017; 9:16148-16158. [PMID: 28443653 DOI: 10.1021/acsami.7b01421] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Borophene, single atomic-layer sheet of boron ( Science 2015 , 350 , 1513 ), is a rather new entrant into the burgeoning class of 2D materials. Borophene exhibits anisotropic metallic properties whereas its hydrogenated counterpart borophane is reported to be a gapless Dirac material lying on the same bench with the celebrated graphene. Interestingly, this transition of borophane also rendered stability to it considering the fact that borophene was synthesized under ultrahigh vacuum conditions on a metallic (Ag) substrate. On the basis of first-principles density functional theory computations, we have investigated the possibilities of borophane as a potential Li/Na-ion battery anode material. We obtained a binding energy of -2.58 (-1.08 eV) eV for Li (Na)-adatom on borophane and Bader charge analysis revealed that Li(Na) atom exists in Li+(Na+) state. Further, on binding with Li/Na, borophane exhibited metallic properties as evidenced by the electronic band structure. We found that diffusion pathways for Li/Na on the borophane surface are anisotropic with x direction being the favorable one with a barrier of 0.27 and 0.09 eV, respectively. While assessing the Li-ion anode performance, we estimated that the maximum Li content is Li0.445B2H2, which gives rises to a material with a maximum theoretical specific capacity of 504 mAh/g together with an average voltage of 0.43 V versus Li/Li+. Likewise, for Na-ion the maximum theoretical capacity and average voltage were estimated to be 504 mAh/g and 0.03 V versus Na/Na+, respectively. These findings unambiguously suggest that borophane can be a potential addition to the map of Li and Na-ion anode materials and can rival some of the recently reported 2D materials including graphene.
Collapse
Affiliation(s)
- Naresh K Jena
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University , Box 516, SE-751 20, Uppsala, Sweden
| | - Rafael B Araujo
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University , Box 516, SE-751 20, Uppsala, Sweden
| | - Vivekanand Shukla
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University , Box 516, SE-751 20, Uppsala, Sweden
| | - Rajeev Ahuja
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University , Box 516, SE-751 20, Uppsala, Sweden
- Applied Materials Physics, Department of Materials and Engineering, Royal Institute of Technology (KTH) , SE-100 44, Stockholm, Sweden
| |
Collapse
|
19
|
George J, Deringer VL, Wang A, Müller P, Englert U, Dronskowski R. Lattice thermal expansion and anisotropic displacements in 𝜶-sulfur from diffraction experiments and first-principles theory. J Chem Phys 2016; 145:234512. [DOI: 10.1063/1.4972068] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Janine George
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Volker L. Deringer
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Ai Wang
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Paul Müller
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Ulli Englert
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Richard Dronskowski
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
- Jülich-Aachen Research Alliance (JARA-HPC), RWTH Aachen University, 52056 Aachen, Germany
| |
Collapse
|
20
|
Xu LC, Du A, Kou L. Hydrogenated borophene as a stable two-dimensional Dirac material with an ultrahigh Fermi velocity. Phys Chem Chem Phys 2016; 18:27284-27289. [DOI: 10.1039/c6cp05405f] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A new 2D in-plane-orbital driven Dirac material, borophane, has an ultrahigh Fermi velocity, which is 4 times higher than that of graphene.
Collapse
Affiliation(s)
- Li-Chun Xu
- College of Physics and Optoelectronics
- Taiyuan University of Technology
- Taiyuan
- China
| | - Aijun Du
- School of Chemistry, Physics, and Mechanical Engineering Faculty
- Queensland University of Technology
- Brisbane
- Australia
| | - Liangzhi Kou
- School of Chemistry, Physics, and Mechanical Engineering Faculty
- Queensland University of Technology
- Brisbane
- Australia
| |
Collapse
|
21
|
Poncé S, Gillet Y, Laflamme Janssen J, Marini A, Verstraete M, Gonze X. Temperature dependence of the electronic structure of semiconductors and insulators. J Chem Phys 2015; 143:102813. [PMID: 26374006 DOI: 10.1063/1.4927081] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The renormalization of electronic eigenenergies due to electron-phonon coupling (temperature dependence and zero-point motion effect) is sizable in many materials with light atoms. This effect, often neglected in ab initio calculations, can be computed using the perturbation-based Allen-Heine-Cardona theory in the adiabatic or non-adiabatic harmonic approximation. After a short description of the recent progresses in this field and a brief overview of the theory, we focus on the issue of phonon wavevector sampling convergence, until now poorly understood. Indeed, the renormalization is obtained numerically through a slowly converging q-point integration. For non-zero Born effective charges, we show that a divergence appears in the electron-phonon matrix elements at q → Γ, leading to a divergence of the adiabatic renormalization at band extrema. This problem is exacerbated by the slow convergence of Born effective charges with electronic wavevector sampling, which leaves residual Born effective charges in ab initio calculations on materials that are physically devoid of such charges. Here, we propose a solution that improves this convergence. However, for materials where Born effective charges are physically non-zero, the divergence of the renormalization indicates a breakdown of the adiabatic harmonic approximation, which we assess here by switching to the non-adiabatic harmonic approximation. Also, we study the convergence behavior of the renormalization and develop reliable extrapolation schemes to obtain the converged results. Finally, the adiabatic and non-adiabatic theories, with corrections for the slow Born effective charge convergence problem (and the associated divergence) are applied to the study of five semiconductors and insulators: α-AlN, β-AlN, BN, diamond, and silicon. For these five materials, we present the zero-point renormalization, temperature dependence, phonon-induced lifetime broadening, and the renormalized electronic band structure.
Collapse
Affiliation(s)
- S Poncé
- European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve, Belgium
| | - Y Gillet
- European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve, Belgium
| | - J Laflamme Janssen
- European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve, Belgium
| | - A Marini
- Consiglio Nazionale delle Ricerche (CNR), Via Salaria Km 29.3, CP 10, 00016 Monterotondo Stazione, Italy
| | - M Verstraete
- European Theoretical Spectroscopy Facility and Physique des matériaux et nanostructures, Université de Liège, Allée du 6 Août 17, B-4000 Liège, Belgium
| | - X Gonze
- European Theoretical Spectroscopy Facility and Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, bte L07.03.01, B-1348 Louvain-la-neuve, Belgium
| |
Collapse
|
22
|
Erba A. On combining temperature and pressure effects on structural properties of crystals with standard ab initio techniques. J Chem Phys 2015; 141:124115. [PMID: 25273420 DOI: 10.1063/1.4896228] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A general-purpose, fully automated, computationally efficient implementation is presented of a series of techniques for the simultaneous description of pressure and temperature effects on structural properties of materials, by means of standard ab initio simulations. Equilibrium volume, bulk modulus, thermal expansion coefficient, equation-of-state, Grüneisen parameter, constant-pressure and constant-volume specific heats are computed as a function of temperature and pressure for the simple crystal of diamond and compared with accurate experimental data. Convergence of computed properties with respect to super-cell size is critically discussed. The effect on such properties of the adopted exchange-correlation functional of the density-functional-theory is discussed by considering three different levels of approximation (including hybrids): it is found to be rather small for the temperature dependence of equilibrium volume and bulk modulus, whereas it is quite large as regards their absolute values.
Collapse
Affiliation(s)
- A Erba
- Dipartimento di Chimica and Centre of Excellence NIS (Nanostructured Interfaces and Surfaces), Università di Torino, via Giuria 5, IT-10125 Torino, Italy
| |
Collapse
|
23
|
Erba A, Shahrokhi M, Moradian R, Dovesi R. On how differently the quasi-harmonic approximation works for two isostructural crystals: Thermal properties of periclase and lime. J Chem Phys 2015; 142:044114. [DOI: 10.1063/1.4906422] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
|
24
|
Perkgöz NK, Sevik C. Vibrational and thermodynamic properties of α-, β-, γ-, and 6, 6, 12-graphyne structures. NANOTECHNOLOGY 2014; 25:185701. [PMID: 24737253 DOI: 10.1088/0957-4484/25/18/185701] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Electronic, vibrational, and thermodynamic properties of different graphyne structures, namely α-, β-, γ-, and 6, 6, 12-graphyne, are investigated through first principles-based quasi-harmonic approximation by using phonon dispersions predicted from density-functional perturbation theory. Similar to graphene, graphyne was shown to exhibit a structure with extraordinary electronic features, mechanical hardness, thermal resistance, and very high conductivity from different calculation methods. Hence, characterizing its phonon dispersions and vibrational and thermodynamic properties in a systematic way is of great importance for both understanding its fundamental molecular properties and also figuring out its phase stability issues at different temperatures. Thus, in this research work, thermodynamic stability of different graphyne allotropes is assessed by investigating vibrational properties, lattice thermal expansion coefficients, and Gibbs free energy. According to our results, although the imaginary vibrational frequencies exist for β-graphyne, there is no such a negative behavior for α-, γ-, and 6, 6, 12-graphyne structures. In general, the Grüneisen parameters and linear thermal expansion coefficients of these structures are calculated to be rather more negative when compared to those of the graphene structure. In addition, the predicted difference between the binding energies per atom for the structures of graphene and graphyne points out that graphyne networks have relatively lower phase stability in comparison with the graphene structures.
Collapse
Affiliation(s)
- Nihan Kosku Perkgöz
- Department of Electrical and Electronics Engineering, Faculty of Engineering, Anadolu University, Eskisehir, TR 26555, Turkey. UNAM-National Nanotechnology Research Center, Bilkent University, Ankara 06800, Turkey
| | | |
Collapse
|
25
|
Xu LC, Wang RZ, Miao MS, Wei XL, Chen YP, Yan H, Lau WM, Liu LM, Ma YM. Two dimensional Dirac carbon allotropes from graphene. NANOSCALE 2014; 6:1113-1118. [PMID: 24296630 DOI: 10.1039/c3nr04463g] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Using a structural search method in combination with first-principles calculations, we found lots of low energy 2D carbon allotropes and examined all possible Dirac points around their Fermi levels. Three amazing 2D Dirac carbon allotropes have been discovered, named as S-graphene, D-graphene and E-graphene. By analyzing the topology correlations among S-, T, net W graphene and graphene, we found that a general rule is valuable for constructing 2D carbon allotropes that are keen to possess Dirac cones in their electronic structures. Based on this rule, we have successfully designed many new 2D carbon allotropes possessing Dirac cones. Their energy order can be well described by an Ising-like model, and some allotropes are energetically more stable than those recently reported. The related electronic structures of these Dirac allotropes are anisotropy distinguished from those of graphene. Moreover, the fact that D- and E-graphene present Dirac cones suggests that sp hybridization or sp(3) hybridization could not suppress the emerging of Dirac features. Our results demonstrate that the Dirac cone and carrier linear dispersion is a very common feature in 2D carbon allotropes and can exist beyond the limitations of fundamental structure features of graphene.
Collapse
Affiliation(s)
- Li-Chun Xu
- College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Wang S, Ye H. First-principles calculation of crystalline materials genome: a preliminary study. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s11434-013-0066-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
27
|
Kozák M, Trojánek F, Galář P, Varga M, Kromka A, Malý P. Coherent phonon dynamics in micro- and nanocrystalline diamond. OPTICS EXPRESS 2013; 21:31521-31529. [PMID: 24514725 DOI: 10.1364/oe.21.031521] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report on the time-resolved coherent anti-Stokes Raman spectroscopy of phonon dephasing in micro- and nanocrystalline diamond films. The dephasing times T(2) were found to be dependent on the morphology of diamond films (average size of crystals and content of nondiamond carbon phase) and changed from 0.7 to 1.72 ps. The dephasing times were found to be temperature independent in the range 10-295 K. In addition to diamond Raman active phonon mode at 1332 cm(-1), we investigated also the dynamics of a broad Raman peak at 1530 cm(-1) which is present in samples with higher content of nondiamond sp(2) hybridized carbon phase. This peak was found to be homogenously broadened with very fast dephasing (T(2)~50 fs).
Collapse
|
28
|
Odkhuu D, Shin D, Ruoff RS, Park N. Conversion of multilayer graphene into continuous ultrathin sp³-bonded carbon films on metal surfaces. Sci Rep 2013; 3:3276. [PMID: 24253851 PMCID: PMC3834869 DOI: 10.1038/srep03276] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/04/2013] [Indexed: 11/09/2022] Open
Abstract
The conversion of multilayer graphenes into sp(3)-bonded carbon films on metal surfaces (through hydrogenation or fluorination of the outer surface of the top graphene layer) is indicated through first-principles computations. The main driving force for this conversion is the hybridization between sp(3) orbitals and metal surface dz(2) orbitals. The induced electronic gap states and spin moments in the carbon layers are confined in a region within 0.5 nm of the metal surface. Whether the conversion occurs depend on the fraction of hydrogenated (fluorinated) C atoms at the outer surface and on the number of stacked graphene layers. In the analysis of the Eliashberg spectral functions for the sp(3) carbon films on a metal surface that is diamagnetic, the strong covalent metal-sp(3) carbon bonds induce soft phonon modes that predominantly contribute to large electron-phonon couplings, suggesting the possibility of phonon-mediated superconductivity. Our computational results suggest a route to experimental realization of large-area ultrathin sp(3)-bonded carbon films on metal surfaces.
Collapse
Affiliation(s)
- Dorj Odkhuu
- Interdisciplinary School of Green Energy and Low Dimensional Carbon Materials Center, Ulsan 689-798, Korea
| | | | | | | |
Collapse
|
29
|
Isberg J, Gabrysch M, Hammersberg J, Majdi S, Kovi KK, Twitchen DJ. Generation, transport and detection of valley-polarized electrons in diamond. NATURE MATERIALS 2013; 12:760-764. [PMID: 23852401 DOI: 10.1038/nmat3694] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 05/22/2013] [Indexed: 06/02/2023]
Abstract
Standard electronic devices encode bits of information by controlling the amount of electric charge in the circuits. Alternatively, it is possible to make devices that rely on other properties of electrons than their charge. For example, spintronic devices make use of the electron spin angular momentum as a carrier of information. A new concept is valleytronics in which information is encoded by the valley quantum number of the electron. The analogy between the valley and spin degrees of freedom also implies the possibility of valley-based quantum computing. In this Article, we demonstrate for the first time generation, transport (across macroscopic distances) and detection of valley-polarized electrons in bulk diamond with a relaxation time of 300 ns at 77 K. We anticipate that these results will form the basis for the development of integrated valleytronic devices.
Collapse
Affiliation(s)
- Jan Isberg
- Division for Electricity, Uppsala University, Box 534, S-751 21 Uppsala, Sweden.
| | | | | | | | | | | |
Collapse
|
30
|
Affiliation(s)
- Christoph E Nebel
- Fraunhofer-Institute for Applied Solid State Physics , Tullastrasse 72, 79108 Freiburg, Germany.
| |
Collapse
|
31
|
Lindsay L, Broido DA, Reinecke TL. First-principles determination of ultrahigh thermal conductivity of boron arsenide: a competitor for diamond? PHYSICAL REVIEW LETTERS 2013; 111:025901. [PMID: 23889420 DOI: 10.1103/physrevlett.111.025901] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Indexed: 05/23/2023]
Abstract
We have calculated the thermal conductivities (κ) of cubic III-V boron compounds using a predictive first principles approach. Boron arsenide is found to have a remarkable room temperature κ over 2000 W m(-1) K(-1); this is comparable to those in diamond and graphite, which are the highest bulk values known. We trace this behavior in boron arsenide to an interplay of certain basic vibrational properties that lie outside of the conventional guidelines in searching for high κ materials, and to relatively weak phonon-isotope scattering. We also find that cubic boron nitride and boron antimonide will have high κ with isotopic purification. This work provides new insight into the nature of thermal transport at a quantitative level and predicts a new ultrahigh κ material of potential interest for passive cooling applications.
Collapse
Affiliation(s)
- L Lindsay
- Naval Research Laboratory, Washington, D.C. 20375, USA
| | | | | |
Collapse
|
32
|
Pascal TA, Karasawa N, Goddard WA. Quantum mechanics based force field for carbon (QMFF-Cx) validated to reproduce the mechanical and thermodynamics properties of graphite. J Chem Phys 2010; 133:134114. [DOI: 10.1063/1.3456543] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
33
|
Porrati F, Sachser R, Strauss M, Andrusenko I, Gorelik T, Kolb U, Bayarjargal L, Winkler B, Huth M. Artificial granularity in two-dimensional arrays of nanodots fabricated by focused-electron-beam-induced deposition. NANOTECHNOLOGY 2010; 21:375302. [PMID: 20720292 DOI: 10.1088/0957-4484/21/37/375302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We have prepared 2D arrays of nanodots embedded in an insulating matrix by means of focused-electron-beam-induced deposition using the W(CO)(6) precursor. By varying the deposition parameters, i.e. the electron beam current and energy and the raster constant, we obtain an artificial granular material with tunable electrical properties. The analysis of the temperature dependence of the conductivity and of the current-voltage characteristic suggests that the transport mechanism is governed by electron tunneling between artificial grains. In order to understand the nature of the granularity and thus the microstructural origin of the electronic transport behavior, we perform TEM and micro-Raman investigations. Independent of the deposition parameters, TEM measurements show that the dots are constituted of amorphous tungsten carbide clusters embedded in an amorphous carbonaceous matrix. Micro-Raman spectra show two peaks, around 690 and 860 cm(-1) associated with the W-C stretching modes. Higher frequency peaks give information on the composition of the matrix. In particular, we measure a peak at about 1290 cm(-1), which is associated with sp(3) carbon bonds. Furthermore we detect the so-called D and G peaks, at about 1350 and 1560 cm(-1), associated with the vibration modes of the sp(2) carbon bonds. The analysis of the position of the peaks and of their relative intensity suggests that the composition of the matrix is between nanocrystalline graphite and amorphous carbon.
Collapse
Affiliation(s)
- F Porrati
- Physikalisches Institut, Goethe-Universität, Frankfurt am Main, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Bartók AP, Payne MC, Kondor R, Csányi G. Gaussian approximation potentials: the accuracy of quantum mechanics, without the electrons. PHYSICAL REVIEW LETTERS 2010; 104:136403. [PMID: 20481899 DOI: 10.1103/physrevlett.104.136403] [Citation(s) in RCA: 924] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Indexed: 05/18/2023]
Abstract
We introduce a class of interatomic potential models that can be automatically generated from data consisting of the energies and forces experienced by atoms, as derived from quantum mechanical calculations. The models do not have a fixed functional form and hence are capable of modeling complex potential energy landscapes. They are systematically improvable with more data. We apply the method to bulk crystals, and test it by calculating properties at high temperatures. Using the interatomic potential to generate the long molecular dynamics trajectories required for such calculations saves orders of magnitude in computational cost.
Collapse
Affiliation(s)
- Albert P Bartók
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, United Kingdom
| | | | | | | |
Collapse
|
35
|
Stoupin S, Shvyd'ko YV. Thermal expansion of diamond at low temperatures. PHYSICAL REVIEW LETTERS 2010; 104:085901. [PMID: 20366949 DOI: 10.1103/physrevlett.104.085901] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Indexed: 05/29/2023]
Abstract
Temperature variation of a lattice parameter of a synthetic diamond crystal (type IIa) was measured using high-energy-resolution x-ray Bragg diffraction in backscattering. A 2 order of magnitude improvement in the measurement accuracy allowed us to directly probe the linear thermal expansion coefficient at temperatures below 100 K. The lowest value measured was 2x10{-9} K-1. It was found that the coefficient deviates from the expected Debye law (T3) while no negative thermal expansion was observed. The anomalous behavior might be attributed to tunneling states due to low concentration impurities.
Collapse
Affiliation(s)
- Stanislav Stoupin
- Advanced Photon Source, Argonne National Laboratory, Illinois 60439, USA
| | | |
Collapse
|
36
|
Xie J, Chen SP, de Gironcoli S, Baroni S. Thermodynamic properties and lattice dynamics of silver at high pressure: A first-principles study. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13642819908214849] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Jianjun Xie
- a Theoretical Division , Los Alamos National Laboratory , Los Alamos , NM , 87545 , USA
| | - S. P. Chen
- a Theoretical Division , Los Alamos National Laboratory , Los Alamos , NM , 87545 , USA
| | - Stefano de Gironcoli
- b Scuola Internazionale Superiore di Studi Avanzati and Istituto Nazionale per la Fisica della Materia , via Beirut 2-4, I-34014 , Trieste , Italy
| | - Stefano Baroni
- b Scuola Internazionale Superiore di Studi Avanzati and Istituto Nazionale per la Fisica della Materia , via Beirut 2-4, I-34014 , Trieste , Italy
| |
Collapse
|
37
|
Verbeni R, D'Astuto M, Krisch M, Lorenzen M, Mermet A, Monaco G, Requardt H, Sette F. Energy calibration of a high-resolution inelastic x-ray scattering spectrometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:083902. [PMID: 19044359 DOI: 10.1063/1.2968118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The energy scale of a triple-axis x-ray spectrometer with meV energy resolution based on perfect silicon crystal optics is calibrated, utilizing the most recent determination of the silicon lattice parameter and its thermal expansion coefficient and recording the dispersion of longitudinal acoustic and optical phonons in a diamond single crystal and the molecular vibration mode in liquid nitrogen. Comparison of the x-ray results with previous inelastic neutron and Raman scattering results as well as with ab initio phonon dispersion calculations yields an overall agreement better than 2%.
Collapse
Affiliation(s)
- Roberto Verbeni
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Li H, Zhou S, Zhang S. The relationship between the thermal expansions and structures of ABO4 oxides. J SOLID STATE CHEM 2007. [DOI: 10.1016/j.jssc.2006.11.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
39
|
Zhuo S, Sohlberg K. Origin of stability of the high-temperature, low-pressure Rh2O3 III form of rhodium sesquioxide. J SOLID STATE CHEM 2006. [DOI: 10.1016/j.jssc.2006.04.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
40
|
Yu H, Yang G, Xiao Y, Yan X, Mao Y, Yang Y, Zhang Y. Lattice dynamics of single-bonded cubic nitrogen. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2005.10.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
41
|
Boeri L, Kortus J, Andersen OK. Three-dimensional MgB2-type superconductivity in hole-doped diamond. PHYSICAL REVIEW LETTERS 2004; 93:237002. [PMID: 15601189 DOI: 10.1103/physrevlett.93.237002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Indexed: 05/24/2023]
Abstract
We substantiate by numerical and analytical calculations that the recently discovered superconductivity below 4 K in 3% boron-doped diamond is caused by electron-phonon coupling of the same type as in MgB2, albeit in three dimensions. Holes at the top of the zone-centered, degenerate sigma-bonding valence-band couple strongly to the optical bond-stretching modes. The increase from two to three dimensions reduces the mode softening crucial for T(c) reaching 40 K in MgB2. Even if diamond had the same bare coupling constant as MgB2, which could be achieved with 10% doping, T(c) would be only 25 K. Superconductivity above 1 K in Si (Ge) requires hole doping beyond 5% (10%).
Collapse
Affiliation(s)
- Lilia Boeri
- INFM SMC and Dipartimento di Fisica, Università la Sapienza, Piazzale Aldo Moro 2, 00185 Rome, Italy
| | | | | |
Collapse
|
42
|
Lee KW, Pickett WE. Superconductivity in boron-doped diamond. PHYSICAL REVIEW LETTERS 2004; 93:237003. [PMID: 15601190 DOI: 10.1103/physrevlett.93.237003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Indexed: 05/24/2023]
Abstract
Superconductivity of boron-doped diamond, reported recently at T(c)=4 K, is investigated exploiting its electronic and vibrational analogies to MgB2. The deformation potential of the hole states arising from the C-C bond-stretch mode is 60% larger than the corresponding quantity in MgB2 that drives its high T(c), leading to very large electron-phonon matrix elements. The calculated coupling strength lambda approximately 0.5 leads to T(c) in the 5-10 K range and makes phonon coupling the likely mechanism. Higher doping should increase T(c) somewhat, but the effects of three dimensionality primarily on the density of states keep doped diamond from having a T(c) closer to that of MgB2.
Collapse
Affiliation(s)
- K-W Lee
- Department of Physics, University of California, Davis, CA 95616, USA
| | | |
Collapse
|
43
|
Ferrari AC, Robertson J. Raman spectroscopy of amorphous, nanostructured, diamond-like carbon, and nanodiamond. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2004; 362:2477-512. [PMID: 15482988 DOI: 10.1098/rsta.2004.1452] [Citation(s) in RCA: 578] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Raman spectroscopy is a standard characterization technique for any carbon system. Here we review the Raman spectra of amorphous, nanostructured, diamond-like carbon and nanodiamond. We show how to use resonant Raman spectroscopy to determine structure and composition of carbon films with and without nitrogen. The measured spectra change with varying excitation energy. By visible and ultraviolet excitation measurements, the G peak dispersion can be derived and correlated with key parameters, such as density, sp(3) content, elastic constants and chemical composition. We then discuss the assignment of the peaks at 1150 and 1480 cm(-1) often observed in nanodiamond. We review the resonant Raman, isotope substitution and annealing experiments, which lead to the assignment of these peaks to trans-polyacetylene.
Collapse
Affiliation(s)
- Andrea Carlo Ferrari
- Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK.
| | | |
Collapse
|
44
|
Occelli F, Loubeyre P, LeToullec R. Properties of diamond under hydrostatic pressures up to 140 GPa. NATURE MATERIALS 2003; 2:151-154. [PMID: 12612670 DOI: 10.1038/nmat831] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2002] [Accepted: 01/06/2003] [Indexed: 05/24/2023]
Abstract
Diamond is the archetypal covalent material. Each atom in an sp(3) configuration is bonded to four nearest neighbours. Because of its remarkable properties, diamond has been extensively studied. And yet our knowledge of the properties of diamond under very high pressure is still incomplete. Although diamond is known to be the preferred allotrope of carbon at high pressure, the possibility of producing under pressure high-density polymorphs of diamond, including metallic forms, has been discussed. Structural changes have already been reported in diamond under non-hydrostatic pressures around 150 GPa and large deformation. However, measurements of the properties of diamond under hydrostatic pressure have been limited to below 40 GPa. Here, we report accurate measurements of the volume and of the optical phonon frequency of diamond under hydrostatic pressure up to 140 GPa. We show that diamond is more compressible than currently expected. By combining the volume and the frequency pressure shifts, we deduce that diamond remains very stable under pressure: it is a Gruneisen solid up to at least 140 GPa, and the covalent bond is even slightly strengthened under pressure. Finally, the optical phonon frequency versus pressure is calibrated here to be used as a pressure gauge for diamond anvil cell studies in the multi-megabar range.
Collapse
Affiliation(s)
- Florent Occelli
- Département de Physique Théorique et Appliquée, CEA/DAM/DIF, 91680 Bruyères-le-Châtel, France
| | | | | |
Collapse
|
45
|
Windl W, Pavone P, Strauch D. Second-order Raman spectrum of AlSb from ab initio phonon calculations and evidence for overbending in the LO phonon branch. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:8580-8585. [PMID: 9984534 DOI: 10.1103/physrevb.54.8580] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
46
|
Mercer JL. Tight-binding models for compounds: Application to SiC. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:4650-4659. [PMID: 9986424 DOI: 10.1103/physrevb.54.4650] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
47
|
Scholze A, Schmidt WG, Bechstedt F. Structure of the diamond (111) surface: Single-dangling-bond versus triple-dangling-bond face. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:13725-13733. [PMID: 9983124 DOI: 10.1103/physrevb.53.13725] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
48
|
Honke R, Fritsch J, Pavone P, Schröder U. Electronic, structural, and dynamical properties of the GaAs(110):Ge surface. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:9923-9929. [PMID: 9982556 DOI: 10.1103/physrevb.53.9923] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
49
|
Karch K, Dietrich T, Windl W, Pavone P, Mayer AP, Strauch D. Contribution of quantum and thermal fluctuations to the elastic moduli and dielectric constants of covalent semiconductors. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:7259-7266. [PMID: 9982173 DOI: 10.1103/physrevb.53.7259] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
50
|
Scandolo S, Chiarotti GL, Tosatti E. SC4: A metallic phase of carbon at terapascal pressures. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:5051-5054. [PMID: 9984087 DOI: 10.1103/physrevb.53.5051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|