1
|
Azizi J, Groß A, Euchner H. Computational Investigation of Carbon Based Anode Materials for Li- and Post-Li- Ion Batteries. ChemSusChem 2024:e202301493. [PMID: 38411370 DOI: 10.1002/cssc.202301493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 02/20/2024] [Accepted: 02/27/2024] [Indexed: 02/28/2024]
Abstract
Due to its negligible capacity with respect to sodium intercalation, graphite is not suited as anode material for sodium ion batteries. Hard carbon materials, on the other hand, provide reasonably high capacities at low insertion potential, making them a promising anode materials for sodium (and potassium) ion batteries. The particular nanostructure of these functionalized carbon-based materials has been found to be crucially linked to the material performance. However, there is still a lack of understanding with respect to the functional role of structural units, such as defects, for intercalation and storage. To overcome these problems, the intercalation of Li, Na, and K in graphitic model structures with distinct defect configurations has been investigated by density functional theory. The calculations confirm that defects are able to stabilize intercalation of larger alkali metal contents. At the same time, it is shown that a combination of phonon and band structure calculations are able to explain characteristic Raman features typically observed for alkali metal intercalation in hard carbon, furthermore allowing for the quantification of the alkali metal intercalation inbetween the layers of hard carbon anodes.
Collapse
Affiliation(s)
- Jafar Azizi
- Institute of Theoretical Chemistry, Ulm University, D-, 89081, Ulm
| | - Axel Groß
- Institute of Theoretical Chemistry, Ulm University, D-, 89081, Ulm
- Helmholtz Institute Ulm for Electrochemical Energy Storage, D-, 89081, Ulm
| | - Holger Euchner
- Institute of Physical and Theoretical Chemistry, University of Tübingen, 72076, Tübingen, Germany
| |
Collapse
|
2
|
Leist J, Kim J, Euchner H, May MM. The relevance of structural variability in the time-domain for computational reflection anisotropy spectroscopy at solid-liquid interfaces. J Phys Condens Matter 2024; 36:185002. [PMID: 38253003 DOI: 10.1088/1361-648x/ad215b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/22/2024] [Indexed: 01/24/2024]
Abstract
In electrochemistry, reactions and charge-transfer are to a large extent determined by the atomistic structure of the solid-liquid interface. Yet due to the presence of the liquid electrolyte, many surface-science methods cannot be applied here. Hence, the exact microscopic structure that is present under operating conditions often remains unknown. Reflection anisotropy spectroscopy (RAS) is one of the few techniques that allow for anin operandoinvestigation of the structure of solid-liquid interfaces. However, an interpretation of RAS data on the atomistic scale can only be obtained by comparison to computational spectroscopy. While the number of computational RAS studies related to electrochemical systems is currently still limited, those studies so far have not taken into account the dynamic nature of the solid-liquid interface. In this work, we investigate the temporal evolution of the spectroscopic response of the Au(110) missing row reconstruction in contact with water by combiningab initiomolecular dynamics with computational spectroscopy. Our results show significant changes in the time evolution of the RA spectra, in particular providing an explanation for the typically observed differences in intensity when comparing theory and experiment. Moreover, these findings point to the importance of structural surface/interface variability while at the same time emphasising the potential of RAS for probing these dynamic interfaces.
Collapse
Affiliation(s)
- Justus Leist
- Universität Ulm, Institute of Theoretical Chemistry, Ulm, Germany
| | - Jongmin Kim
- Universität Ulm, Institute of Theoretical Chemistry, Ulm, Germany
- Universität Tübingen, Institute of Physical and Theoretical Chemistry, Tübingen, Germany
| | - Holger Euchner
- Universität Tübingen, Institute of Physical and Theoretical Chemistry, Tübingen, Germany
| | - Matthias M May
- Universität Ulm, Institute of Theoretical Chemistry, Ulm, Germany
- Universität Tübingen, Institute of Physical and Theoretical Chemistry, Tübingen, Germany
| |
Collapse
|
3
|
Brant WR, Koriukina T, Chien YC, Euchner H, Sanz J, Kuhn A, Heinzmann R, Indris S, Schmid S. Local structure transformations promoting high lithium diffusion in defect perovskite type structures. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
4
|
Sharma P, Minakshi Sundaram M, Watcharatharapong T, Laird D, Euchner H, Ahuja R. Zn Metal Atom Doping on the Surface Plane of One-Dimesional NiMoO 4 Nanorods with Improved Redox Chemistry. ACS Appl Mater Interfaces 2020; 12:44815-44829. [PMID: 32930565 DOI: 10.1021/acsami.0c13755] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The effect of zinc (Zn) doping and defect formation on the surface of nickel molybdate (NiMoO4) structures with varying Zn content has been studied to produce one-dimensional electrodes and catalysts for electrochemical energy storage and ethanol oxidation, respectively. Zn-doped nickel molybdate (Ni1-xZnxMoO4, where x = 0.1, 0.2, 0.4, and 0.6) nanorods were synthesized by a simple wet chemical route. The optimal amount of Zn is found to be around 0.25 above which the NiMoO4 becomes unstable, resulting in poor electrochemical activity. This result agrees with our density functional theory calculations in which the thermodynamic stability reveals that Ni1-xZnxMoO4 crystallized in the β-NiMoO4 phase and is found to be stable for x≤0.25. Analytical techniques show direct evidence of the presence of Zn in the NiMoO4 nanorods, which subtly alter the electrocatalytic activity. Compared with pristine NiMoO4, Zn-doped NiMoO4 with the optimized Zn content was tested as an electrode for an asymmetric supercapacitor and demonstrated an enhanced specific capacitance of 122 F g-1 with a high specific energy density of 43 W h kg-1 at a high power density of 384 W kg-1. Our calculations suggest that the good conductivity from Zn doping is attributed to the formation of excess oxygen vacancies and dopants play an important role in enhancing the charge transfer between the surface and OH- ions from the electrolyte. We report electrochemical testing, material characterization, and computational insights and demonstrate that the appropriate amount of Zn in NiMoO4 can improve the storage capacity (∼15%) due to oxygen vacancy interactions.
Collapse
Affiliation(s)
- Pratigya Sharma
- School of Engineering and Information Technology, Murdoch University, Murdoch, WA 6150, Australia
| | | | | | - Damian Laird
- School of Engineering and Information Technology, Murdoch University, Murdoch, WA 6150, Australia
| | - Holger Euchner
- Helmholtz Institute Ulm (HIU), Helmholtzstraße, Ulm 1189081, Germany
| | - Rajeev Ahuja
- Condensed Matter Theory group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala, Sweden
| |
Collapse
|
5
|
Liu X, Euchner H, Zarrabeitia M, Gao X, Elia GA, Groß A, Passerini S. Operando pH Measurements Decipher H +/Zn 2+ Intercalation Chemistry in High-Performance Aqueous Zn/δ-V 2O 5 Batteries. ACS Energy Lett 2020; 5:2979-2986. [PMID: 35663051 PMCID: PMC9161344 DOI: 10.1021/acsenergylett.0c01767] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 08/24/2020] [Indexed: 05/22/2023]
Abstract
Vanadium oxides have been recognized to be among the most promising positive electrode materials for aqueous zinc metal batteries (AZMBs). However, their underlying intercalation mechanisms are still vigorously debated. To shed light on the intercalation mechanisms, high-performance δ-V2O5 is investigated as a model compound. Its structural and electrochemical behaviors in the designed cells with three different electrolytes, i.e., 3 m Zn(CF3SO3)2/water, 0.01 M H2SO4/water, and 1 M Zn(CF3SO3)2/acetonitrile, demonstrate that the conventional structural and elemental characterization methods cannot adequately clarify the separate roles of H+ and Zn2+ intercalations in the Zn(CF3SO3)2/water electrolyte. Thus, an operando pH determination method is developed and used toward Zn/δ-V2O5 AZMBs. This method indicates the intercalation of both H+ and Zn2+ into δ-V2O5 and uncovers an unusual H+/Zn2+-exchange intercalation-deintercalation mechanism. Density functional theory calculations further reveal that the H+/Zn2+ intercalation chemistry is a consequence of the variation of the electrochemical potential of Zn2+ and H+ during the electrochemical intercalation/release.
Collapse
Affiliation(s)
- Xu Liu
- Helmholtz
Institute Ulm (HIU), Helmholtzstrasse 11, D-89081 Ulm, Germany
- Karlsruhe
Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Holger Euchner
- Helmholtz
Institute Ulm (HIU), Helmholtzstrasse 11, D-89081 Ulm, Germany
| | - Maider Zarrabeitia
- Helmholtz
Institute Ulm (HIU), Helmholtzstrasse 11, D-89081 Ulm, Germany
- Karlsruhe
Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
- Centre
for Cooperative Research on Alternative Energies (CIC energiGUNE), Basque Research and Technology Alliance (BRTA), Alava Technology Park, Albert Einstein
48, 01510 Vitoria-Gasteiz, Spain
| | - Xinpei Gao
- Helmholtz
Institute Ulm (HIU), Helmholtzstrasse 11, D-89081 Ulm, Germany
- Karlsruhe
Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Giuseppe Antonio Elia
- Helmholtz
Institute Ulm (HIU), Helmholtzstrasse 11, D-89081 Ulm, Germany
- Karlsruhe
Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Axel Groß
- Helmholtz
Institute Ulm (HIU), Helmholtzstrasse 11, D-89081 Ulm, Germany
- University
of Ulm, Institute of Theoretical
Chemistry, Albert-Einstein-Allee
11, D-89081 Ulm, Germany
| | - Stefano Passerini
- Helmholtz
Institute Ulm (HIU), Helmholtzstrasse 11, D-89081 Ulm, Germany
- Karlsruhe
Institute of Technology (KIT), P.O. Box 3640, D-76021 Karlsruhe, Germany
| |
Collapse
|
6
|
Cambaz MA, Vinayan BP, Euchner H, Pervez SA, Geßwein H, Braun T, Gross A, Fichtner M. Design and Tuning of the Electrochemical Properties of Vanadium-Based Cation-Disordered Rock-Salt Oxide Positive Electrode Material for Lithium-Ion Batteries. ACS Appl Mater Interfaces 2019; 11:39848-39858. [PMID: 31589014 DOI: 10.1021/acsami.9b12566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Disordered rock-salt compounds are becoming increasingly important due to their potential as high-capacity positive electrode materials for lithium-ion batteries. Thereby, a significant number of studies have focused on increasing the accessible Li capacity, but studies to manipulate the electrochemical potential are limited. This work explores the effect of transition-metal substitution on the electrochemistry of ternary disordered rock-salt-type compounds with LiM2+0.5V0.54+O2 stoichiometry (M = Mn, Fe, Co) directly synthesized through mechanochemistry. Rietveld refinements of synchrotron X-ray diffraction patterns confirm the disordered rock-salt structures. First-principles density functional theory study is used to predict the impact of the cation substitution on the expected average voltage and the electronic structures of these materials are used to analyze the underlying redox processes. For LiM2+0.5V4+0.5O2 (M = Mn, Fe, Co), discharge voltages increase in the order of Mn < Fe < Co with 2.28, 2.41, and 2.51 V, exhibiting discharge capacities of 219, 207, and 234 mAh g-1, respectively. In comparison, for the disordered rock-salt Li2VO3, an average discharge voltage of ∼2.2 V with V5+/4+ redox couple has been reported. However, detrimental electrode-electrolyte interactions manifested as transition-metal dissolution has been found to result in severe capacity fading. Thereto, the use of a concentrated 5.5 M LiFSI increased the cycling stability significantly, effectively reducing transition-metal dissolution. The underlying reasons for the capacity fading of disordered rock salts are yet unclear. We stress the importance of cathode-electrolyte interactions, thus opening new directions for the improvement of cation-disordered materials.
Collapse
Affiliation(s)
- Musa Ali Cambaz
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstr. 11 , 89081 Ulm , Germany
| | - Bhaghavathi P Vinayan
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstr. 11 , 89081 Ulm , Germany
| | - Holger Euchner
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstr. 11 , 89081 Ulm , Germany
- Institute of Theoretical Chemistry , Ulm University , 89069 Ulm , Germany
| | - Syed Atif Pervez
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstr. 11 , 89081 Ulm , Germany
| | | | - Tobias Braun
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstr. 11 , 89081 Ulm , Germany
| | - Axel Gross
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstr. 11 , 89081 Ulm , Germany
- Institute of Theoretical Chemistry , Ulm University , 89069 Ulm , Germany
| | - Maximilian Fichtner
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstr. 11 , 89081 Ulm , Germany
| |
Collapse
|
7
|
Cambaz MA, Vinayan BP, Euchner H, Johnsen RE, Guda AA, Mazilkin A, Rusalev YV, Trigub AL, Gross A, Fichtner M. Design of Nickel-Based Cation-Disordered Rock-Salt Oxides: The Effect of Transition Metal (M = V, Ti, Zr) Substitution in LiNi 0.5M 0.5O 2 Binary Systems. ACS Appl Mater Interfaces 2018; 10:21957-21964. [PMID: 29863834 DOI: 10.1021/acsami.8b02266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cation-disordered oxides have been ignored as positive electrode material for a long time due to structurally limited lithium insertion/extraction capabilities. In this work, a case study is carried out on nickel-based cation-disordered Fm3 ̅m LiNi0.5M0.5O2 positive electrode materials. The present investigation targets tailoring the electrochemical properties for nickel-based cation-disordered rock-salt by electronic considerations. The compositional space for binary LiM+3O2 with metals active for +3/+4 redox couples is extended to ternary oxides with LiA0.5B0.5O2 with A = Ni2+ and B = Ti4+, Zr4+, and V+4 to assess the impact of the different transition metals in the isostructural oxides. The direct synthesis of various new unknown ternary nickel-based Fm3̅ m cation-disordered rock-salt positive electrode materials is presented with a particular focus on the LiNi0.5V0.5O2 system. This positive electrode material for Li-ion batteries displays an average voltage of ∼2.55 V and a high discharge capacity of 264 mAhg-1 corresponding to 0.94 Li. For appropriate cutoff voltages, a long cycle life is achieved. The charge compensation mechanism is probed by XANES, confirming the reversible oxidation and reduction of V4+/V5+. The enhancement in the electrochemical performances within the presented compounds stresses the importance of mixed cation-disordered transition metal oxides with different electronic configuration.
Collapse
Affiliation(s)
- Musa Ali Cambaz
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstrasse 11 , 89081 Ulm , Germany
| | - Bhaghavathi P Vinayan
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstrasse 11 , 89081 Ulm , Germany
| | - Holger Euchner
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstrasse 11 , 89081 Ulm , Germany
- Institute of Theoretical Chemistry , Ulm University , 89069 Ulm , Germany
| | - Rune E Johnsen
- Department of Energy Conversion and Storage , Technical University of Denmark , Frederiksborgvej 399 , 4000 Roskilde , Denmark
| | - Alexander A Guda
- International Research Center "Smart Materials" , Southern Federal University , Sladkova 178/24 , 344090 Rostov-on-Don , Russia
| | - Andrey Mazilkin
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT) , P.O. Box 3640, 76021 Karlsruhe , Germany
| | - Yury V Rusalev
- International Research Center "Smart Materials" , Southern Federal University , Sladkova 178/24 , 344090 Rostov-on-Don , Russia
| | - Alexander L Trigub
- National Research Centre "Kurchatov Institute" , 1 Akademika Kurchatova pl. , 123098 Moscow , Russia
- Institute of Geology of Ore Deposits (IGEM RAS) , 35, Staromonetnyi per. , 119017 Moscow , Russia
| | - Axel Gross
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstrasse 11 , 89081 Ulm , Germany
- Institute of Theoretical Chemistry , Ulm University , 89069 Ulm , Germany
| | - Maximilian Fichtner
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) , Helmholtzstrasse 11 , 89081 Ulm , Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT) , P.O. Box 3640, 76021 Karlsruhe , Germany
| |
Collapse
|
8
|
Yamada T, Takakura H, Euchner H, Pay Gomez C, Kong T, Canfield P, Goldman A, de Boissieu M. Atomic structures of the Sc–Zn and R–Cd icosahedral quasicrystals. Acta Crystallogr A Found Adv 2017. [DOI: 10.1107/s2053273317082584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
9
|
Lory PF, Pailhès S, Giordano VM, Euchner H, Nguyen HD, Ramlau R, Borrmann H, Schmidt M, Baitinger M, Ikeda M, Tomeš P, Mihalkovič M, Allio C, Johnson MR, Schober H, Sidis Y, Bourdarot F, Regnault LP, Ollivier J, Paschen S, Grin Y, de Boissieu M. Direct measurement of individual phonon lifetimes in the clathrate compound Ba 7.81Ge 40.67Au 5.33. Nat Commun 2017; 8:491. [PMID: 28887470 PMCID: PMC5591192 DOI: 10.1038/s41467-017-00584-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 07/10/2017] [Indexed: 11/09/2022] Open
Abstract
Engineering lattice thermal conductivity requires to control the heat carried by atomic vibration waves, the phonons. The key parameter for quantifying it is the phonon lifetime, limiting the travelling distance, whose determination is however at the limits of instrumental capabilities. Here, we show the achievement of a direct quantitative measurement of phonon lifetimes in a single crystal of the clathrate Ba7.81Ge40.67Au5.33, renowned for its puzzling ‘glass-like’ thermal conductivity. Surprisingly, thermal transport is dominated by acoustic phonons with long lifetimes, travelling over distances of 10 to 100 nm as their wave-vector goes from 0.3 to 0.1 Å−1. Considering only low-energy acoustic phonons, and their observed lifetime, leads to a calculated thermal conductivity very close to the experimental one. Our results challenge the current picture of thermal transport in clathrates, underlining the inability of state-of-the-art simulations to reproduce the experimental data, thus representing a crucial experimental input for theoretical developments. Phonon lifetime is a fundamental parameter of thermal transport however its determination is challenging. Using inelastic neutron scattering and the neutron resonant spin-echo technique, Lory et al. determine the acoustic phonon lifetime in a single crystal of clathrate Ba7.81Ge40.67Au5.33.
Collapse
Affiliation(s)
- Pierre-François Lory
- Institut Laue-Langevin, Grenoble, F-38000, France.,University Grenoble Alpes, CNRS, Grenoble-INP, SIMaP, F-38000, Grenoble, France
| | - Stéphane Pailhès
- University Lyon, University Claude Bernard Lyon 1, CNRS, Institute of Light and Matter, F-69622, Villeurbanne, France.
| | - Valentina M Giordano
- University Lyon, University Claude Bernard Lyon 1, CNRS, Institute of Light and Matter, F-69622, Villeurbanne, France
| | - Holger Euchner
- Institute of Materials Science and Technology, Vienna University of Technology, 1040, Vienna, Austria
| | - Hong Duong Nguyen
- Max-Planck-Institut für Chemische Physik fester Stoffe, 01187, Dresden, Germany
| | - Reiner Ramlau
- Max-Planck-Institut für Chemische Physik fester Stoffe, 01187, Dresden, Germany
| | - Horst Borrmann
- Max-Planck-Institut für Chemische Physik fester Stoffe, 01187, Dresden, Germany
| | - Marcus Schmidt
- Max-Planck-Institut für Chemische Physik fester Stoffe, 01187, Dresden, Germany
| | - Michael Baitinger
- Max-Planck-Institut für Chemische Physik fester Stoffe, 01187, Dresden, Germany
| | - Matthias Ikeda
- Institute of Solid State Physics, Vienna University of Technology, 1040, Vienna, Austria
| | - Petr Tomeš
- Institute of Solid State Physics, Vienna University of Technology, 1040, Vienna, Austria
| | - Marek Mihalkovič
- Institute of Physics, Slovak Academy of Sciences, 84511, Bratislava, Slovakia
| | - Céline Allio
- Physikalisches Institut, Goethe-University, 60438, Frankfurt, Germany
| | | | - Helmut Schober
- Institut Laue-Langevin, Grenoble, F-38000, France.,University Grenoble Alpes, UFR PhITEM, F-38000, Grenoble, France
| | - Yvan Sidis
- Laboratoire Léon Brillouin, CNRS, CEA, UMR-12, 91191, Gif sur Yvette, France
| | | | | | | | - Silke Paschen
- Institute of Solid State Physics, Vienna University of Technology, 1040, Vienna, Austria
| | - Yuri Grin
- Max-Planck-Institut für Chemische Physik fester Stoffe, 01187, Dresden, Germany
| | - Marc de Boissieu
- University Grenoble Alpes, CNRS, Grenoble-INP, SIMaP, F-38000, Grenoble, France.
| |
Collapse
|
10
|
Gschwind F, Euchner H, Rodriguez-Garcia G. Chloride Ion Battery Review: Theoretical Calculations, State of the Art, Safety, Toxicity, and an Outlook towards Future Developments. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700288] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Fabienne Gschwind
- Helmholtz Institute Ulm (HIU); Helmholtzstrasse 11 89081 Ulm Germany
| | - Holger Euchner
- Helmholtz Institute Ulm (HIU); Helmholtzstrasse 11 89081 Ulm Germany
| | - Gonzalo Rodriguez-Garcia
- Institute of Fluid Dynamics; Helmholtz-Zentrum Dresden-Rossendorf (HZDR); Bautzner Landstrasse 400 01328 Dresden Germany
| |
Collapse
|
11
|
de Boissieu M, Yamada T, Takakura H, Euchner H, Pay-Gomez C, Bosak A, Fertey P. Atomic structure and phason modes of the Sc-Zn icosahedral quasicrystal. Acta Crystallogr A Found Adv 2016. [DOI: 10.1107/s2053273316098594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
12
|
Yamada T, Takakura H, Euchner H, Pay Gómez C, Bosak A, Fertey P, de Boissieu M. Atomic structure and phason modes of the Sc-Zn icosahedral quasicrystal. IUCrJ 2016; 3:247-58. [PMID: 27437112 PMCID: PMC4937780 DOI: 10.1107/s2052252516007041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 04/26/2016] [Indexed: 06/06/2023]
Abstract
The detailed atomic structure of the binary icosahedral (i) ScZn7.33 quasicrystal has been investigated by means of high-resolution synchrotron single-crystal X-ray diffraction and absolute scale measurements of diffuse scattering. The average atomic structure has been solved using the measured Bragg intensity data based on a six-dimensional model that is isostructural to the i-YbCd5.7 one. The structure is described with a quasiperiodic packing of large Tsai-type rhombic triacontahedron clusters and double Friauf polyhedra (DFP), both resulting from a close-packing of a large (Sc) and a small (Zn) atom. The difference in chemical composition between i-ScZn7.33 and i-YbCd5.7 was found to lie in the icosahedron shell and the DFP where in i-ScZn7.33 chemical disorder occurs on the large atom sites, which induces a significant distortion to the structure units. The intensity in reciprocal space displays a substantial amount of diffuse scattering with anisotropic distribution, located around the strong Bragg peaks, that can be fully interpreted as resulting from phason fluctuations, with a ratio of the phason elastic constants K 2/K 1 = -0.53, i.e. close to a threefold instability limit. This induces a relatively large perpendicular (or phason) Debye-Waller factor, which explains the vanishing of 'high-Q perp' reflections.
Collapse
Affiliation(s)
- Tsunetomo Yamada
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Miyagi 980-8577, Japan
| | - Hiroyuki Takakura
- Division of Applied Physics, Faculty of Engineering, Hokkaido University, Hokkaido 060-8628, Japan
| | - Holger Euchner
- Institute of Materials Science and Technology, Vienna University of Technology, Vienna 1040, Austria
| | - Cesar Pay Gómez
- Department of Chemistry, Ångström Laboratory, Uppsala University, Uppsala 751 21, Sweden
| | - Alexei Bosak
- ESRF – The European Synchrotron, Grenoble F-38043, France
| | | | - Marc de Boissieu
- Université Grenoble Alpes, SIMAP, Grenoble F-38000, France
- CNRS, SIMAP, Grenoble F-38000, France
| |
Collapse
|
13
|
Euchner H, Mayrhofer P. Vacancy-dependent stability of cubic and wurtzite Ti 1-x Al x N. Surf Coat Technol 2015; 275:214-218. [PMID: 26412921 PMCID: PMC4567048 DOI: 10.1016/j.surfcoat.2015.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/15/2015] [Accepted: 05/12/2015] [Indexed: 06/05/2023]
Abstract
While it is well-known that supersaturated cubic-structured Ti1-x Al x N can be prepared by physical vapor deposition, the impact of point defects on formation process and cubic to wurtzite transition is largely unexplored. Irrespective of point defects, ab initio calculations correctly predict the Al concentration of the cubic to wurtzite transition. By means of density functional theory we show that vacancies on metal and/or non-metal sites only slightly affect the cubic to wurtzite transition region, whereas they clearly affect the physical properties.
Collapse
Affiliation(s)
- H. Euchner
- Corresponding author at: Getreidemarkt 9, 1060 Vienna, Austria.
| | | |
Collapse
|
14
|
Euchner H, Mayrhofer P. Designing thin film materials - Ternary borides from first principles. Thin Solid Films 2015; 583:46-49. [PMID: 26082562 PMCID: PMC4456063 DOI: 10.1016/j.tsf.2015.03.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 03/10/2015] [Accepted: 03/16/2015] [Indexed: 06/04/2023]
Abstract
Exploiting the mechanisms responsible for the exceptional properties of aluminum based nitride coatings, we apply ab initio calculations to develop a recipe for designing functional thin film materials based on ternary diborides. The combination of binary diborides, preferring different structure types, results in supersaturated metastable ternary systems with potential for phase transformation induced effects. For the exemplary cases of M x W1 - x B2 (with M = Al, Ti, V) we show by detailed ab initio calculations that the respective ternary solid solutions are likely to be experimentally accessible by modern depositions techniques.
Collapse
Affiliation(s)
- H. Euchner
- Corresponding author at: Getreidemarkt 9, 1160 Vienna, Austria. Tel.: + 43 1 58801 30843; fax: + 43 1 58801 30895.
| | | |
Collapse
|
15
|
Mayrhofer PM, Euchner H, Bittner A, Schmid U. Circular test structure for the determination of piezoelectric constants of Sc x Al 1-x N thin films applying Laser Doppler Vibrometry and FEM simulations. Sens Actuators A Phys 2015; 222:301-308. [PMID: 26109748 PMCID: PMC4461150 DOI: 10.1016/j.sna.2014.10.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 10/15/2014] [Accepted: 10/21/2014] [Indexed: 06/04/2023]
Abstract
Piezoelectric scandium aluminium nitride (Sc x Al1-x N) thin films offer a large potential for the application in micro electromechanical systems, as advantageous properties of pure AlN thin films are maintained, but combined with an increased piezoelectric actuation and sensing potential. Sc x Al1-x N thin films with x = 27% have been prepared by DC reactive magnetron sputtering to find optimized deposition parameters to maximize the piezoelectric constants d33 and d31. For the accurate and simultaneous measurement of these constants Laser Doppler Vibrometry has been applied and compared to finite element (FEM) simulations. The electrode design has been optimized to rotational symmetric structures enabling a 180° phase shifted excitation, so that a straight-forward comparison of experimental displacement curves with those obtained from FEM is feasible.
Collapse
Affiliation(s)
- P M Mayrhofer
- Institute of Sensor and Actuator Systems, Vienna University of Technology, Floragasse 7, 1040 Vienna, Austria
| | - H Euchner
- Institute of Materials Science and Technology, Vienna University of Technology, Karlsplatz 13, 1040 Vienna, Austria
| | - A Bittner
- Institute of Sensor and Actuator Systems, Vienna University of Technology, Floragasse 7, 1040 Vienna, Austria
| | - U Schmid
- Institute of Sensor and Actuator Systems, Vienna University of Technology, Floragasse 7, 1040 Vienna, Austria
| |
Collapse
|
16
|
Hollerweger R, Holec D, Paulitsch J, Bartosik M, Daniel R, Rachbauer R, Polcik P, Keckes J, Krywka C, Euchner H, Mayrhofer P. Complementary ab initio and X-ray nanodiffraction studies of Ta 2O 5. Acta Mater 2015; 83:276-284. [PMID: 25642136 PMCID: PMC4308001 DOI: 10.1016/j.actamat.2014.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 09/25/2014] [Accepted: 10/03/2014] [Indexed: 05/14/2023]
Abstract
The complex structure of Ta2O5 led to the development of various structural models. Among them, superstructures represent the most stable configurations. However, their formation requires kinetic activity and long-range ordering processes, which are hardly present during physical vapor deposition. Based on nano-beam X-ray diffraction and concomitant ab initio studies, a new metastable orthorhombic basic structure is introduced for Ta2O5 with lattice parameters a = 6.425 Å, b = 3.769 Å and c = 7.706 Å. The unit cell containing only 14 atoms, i.e. two formula unit blocks in the c direction, is characterized by periodically alternating the occupied oxygen site between two possible positions in succeeding 002-planes. This structure can be described by the space group 53 (Pncm) with four Wyckoff positions, and exhibits an energy of formation of -3.209 eV atom-1. Among all the reported basic structures, its energy of formation is closest to those of superstructures. Furthermore, this model exhibits a 2.5 eV band gap, which is closer to experimental data than the band gap of any other basic-structure model. The sputtered Ta2O5 films develop only a superstructure if annealed at temperatures >800 °C in air or vacuum. Based on these results and the conveniently small unit cell size, it is proposed that the basic-structure model described here is an ideal candidate for both structure and electronic state descriptions of orthorhombic Ta2O5 materials.
Collapse
Affiliation(s)
- R. Hollerweger
- Christian Doppler Laboratory for Application Oriented Coating Development at the Institute of Materials Science and Technology, Vienna University of Technology, A-1040 Vienna, Austria
- Corresponding author.
| | - D. Holec
- Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, A-8700 Leoben, Austria
| | - J. Paulitsch
- Institute of Materials Science and Technology, Vienna University of Technology, A-1040 Vienna, Austria
| | - M. Bartosik
- Christian Doppler Laboratory for Application Oriented Coating Development at the Institute of Materials Science and Technology, Vienna University of Technology, A-1040 Vienna, Austria
| | - R. Daniel
- Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, A-8700 Leoben, Austria
| | - R. Rachbauer
- Oerlikon Balzers Coating AG, LI-9496 Balzers, Liechtenstein
| | - P. Polcik
- Plansee Composite Materials GmbH, D-86983 Lechbruck am See, Germany
| | - J. Keckes
- Department Materials Physics, Montanuniversität Leoben and Materials Center Leoben, A-8700 Leoben, Austria
| | - C. Krywka
- Ruprecht Haensel Laboratory, University of Kiel, Leibnizstrasse 19, D-24098 Kiel and Helmholtz-Zentrum Geesthacht, Institute for Materials Research, D-21502 Geesthacht, Germany
| | - H. Euchner
- Institute of Materials Science and Technology, Vienna University of Technology, A-1040 Vienna, Austria
| | - P.H. Mayrhofer
- Christian Doppler Laboratory for Application Oriented Coating Development at the Institute of Materials Science and Technology, Vienna University of Technology, A-1040 Vienna, Austria
- Institute of Materials Science and Technology, Vienna University of Technology, A-1040 Vienna, Austria
| |
Collapse
|
17
|
Pailhès S, Euchner H, Giordano VM, Debord R, Assy A, Gomès S, Bosak A, Machon D, Paschen S, de Boissieu M. Localization of propagative phonons in a perfectly crystalline solid. Phys Rev Lett 2014; 113:025506. [PMID: 25062208 DOI: 10.1103/physrevlett.113.025506] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Indexed: 06/03/2023]
Abstract
Perfectly crystalline solids are excellent heat conductors. Prominent counterexamples are intermetallic clathrates, guest-host systems with a high potential for thermoelectric applications due to their ultralow thermal conductivities. Our combined experimental and theoretical investigation of the lattice dynamics of a particularly simple binary representative, Ba(8)Si(46), identifies the mechanism responsible for the reduction of lattice thermal conductivity intrinsic to the perfect crystal structure. Above a critical wave vector, the purely harmonic guest-host interaction leads to a drastic transfer of spectral weight to the guest atoms, corresponding to a localization of the propagative phonons.
Collapse
Affiliation(s)
- S Pailhès
- Institute of Light and Matter, UMR5306 Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne cedex, France
| | - H Euchner
- Institut für Theoretische und Angwandte Physik, Universität Stuttgart, D-70550 Stuttgart, Germany and Institute of Materials Science and Technology, Vienna University of Technology, A-1040 Vienna, Austria
| | - V M Giordano
- Institute of Light and Matter, UMR5306 Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne cedex, France and CNRS, SIMAP, F-38000 Grenoble, France
| | - R Debord
- Institute of Light and Matter, UMR5306 Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne cedex, France
| | - A Assy
- Université de Lyon, INSA-Lyon, CETHIL UMR5008, F-69621 Villeurbanne, France
| | - S Gomès
- Université de Lyon, CNRS, CETHIL UMR5008, F-69621, France
| | - A Bosak
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble cedex, France
| | - D Machon
- Institute of Light and Matter, UMR5306 Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne cedex, France
| | - S Paschen
- Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
| | - M de Boissieu
- Université Grenoble Alpes, SIMAP, F-38000 Grenoble, France and CNRS, SIMAP, F-38000 Grenoble, France
| |
Collapse
|
18
|
Euchner H, Yamada T, Rols S, Ishimasa T, Ollivier J, Schober H, Mihalkovic M, de Boissieu M. Lattice dynamics of the icosahedral quasicrystals i-ZnMgSc and i-ZnAgSc and the cubic 1/1-approximant Zn6Sc. J Phys Condens Matter 2014; 26:055402. [PMID: 24445750 DOI: 10.1088/0953-8984/26/5/055402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A comparison of periodic approximants and their quasicrystalline counterparts offers the opportunity to better understand the structure, physical properties and stabilizing mechanisms of these complex phases. We present a combined experimental and computational study of the lattice dynamics of the icosahedral quasicrystals i-ZnMgSc and i-ZnAgSc and compare these to the lattice dynamics of the cubic 1/1-approximant Zn6Sc. The two phases, quasicrystal and approximant, are built up from the same atomic clusters, which are packed either quasiperiodically or on a body centered cubic lattice, respectively. Using inelastic neutron scattering and atomic scale simulations, we show that the vibrational spectra of these three systems are very similar, however, they contain a clear signature of the increasing structural complexity from approximant to quasicrystal.
Collapse
|
19
|
Yamada T, Euchner H, Gómez CP, Takakura H, Tamura R, de Boissieu M. Short- and long-range ordering during the phase transition of the Zn6Sc 1/1 cubic approximant. J Phys Condens Matter 2013; 25:205405. [PMID: 23614939 DOI: 10.1088/0953-8984/25/20/205405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Using in situ x-ray scattering and synchrotron radiation, we have experimentally elucidated the mechanism of the cubic to monoclinic phase transition in the Zn6Sc 1/1 approximant to an icosahedral quasicrystal. The high-temperature cubic phase is described as a bcc packing of a large Tsai-type icosahedral cluster whose center is occupied by an orientationally disordered Zn4 tetrahedron. A clear monoclinic distortion has been found to take place within 2 K around Tc = 157 K, in excellent agreement with the observed anomalies in the electrical resistivity and heat capacity. Also, a rapid variation of the super-structure reflection intensity is observed. The low-temperature monoclinic phase, as determined by single-crystal x-ray diffraction at 40 K, has been confirmed to consist of ordered Zn4 tetrahedra, oriented in an anti-parallel way along the [[Formula: see text]] direction. Above Tc, a diffuse scattering signal is observed at the position of the super-structure reflections, which evidences that a short-range ordering of the Zn4 tetrahedra takes place. In a way similar to a second-order phase transition, the correlation length describing this short-range ordering increases rapidly when the temperature diminishes and almost diverges when the temperature is close to Tc, going from 200 Å at 220 K to reach the very large value of 1200 Å at 161 K. Finally, using single-crystal x-ray diffraction, the atomic structure of the low-temperature monoclinic super-structure (space group C2/c) could be solved. The ordering of the Zn4 tetrahedra is accompanied by a strong distortion of the surrounding shells.
Collapse
Affiliation(s)
- Tsunetomo Yamada
- Department of Materials Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | | | | | | | | | | |
Collapse
|
20
|
Euchner H, Yamada T, Rols S, Ishimasa T, Kaneko Y, Ollivier J, Schober H, Mihalkovic M, de Boissieu M. Tetrahedron dynamics in the icosahedral quasicrystals i-ZnMgSc and i-ZnAgSc and the cubic 1/1-approximant Zn6Sc. J Phys Condens Matter 2013; 25:115405. [PMID: 23411496 DOI: 10.1088/0953-8984/25/11/115405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A comparison of periodic approximants and their quasicrystalline counterparts offers the opportunity to better understand the structure, physical properties and stabilizing mechanisms of these complex phases. We present a combined experimental and molecular dynamics study of the lattice dynamics of the icosahedral quasicrystals i-ZnMgSc and i-ZnAgSc and compare it to recently published results obtained for the cubic 1/1-approximant Zn(6)Sc. Both phases, quasicrystal and approximant, are built up from large atomic clusters which contain a tetrahedral shell at the cluster centre and are packed either quasiperiodically or on a bcc lattice. Using quasielastic neutron scattering and atomic scale simulations, we show that in the quasicrystal the tetrahedra display a dynamics similar to that observed in the 1/1-approximant: the tetrahedra behave as a 'single molecule' and reorient dynamically on a timescale of the order of a few ps. The tetrahedra reorientation is accompanied by a large distortion of the surrounding cluster shells which provide a unique dynamical flexibility to the quasicrystal. However, whereas in the 1/1-approximant the tetrahedron reorientation is observed down to T(c) = 160 K, where a phase transition takes place, in the quasicrystal the tetrahedron dynamics is gradually freezing from 550 to 300 K, similarly to a glassy system.
Collapse
Affiliation(s)
- H Euchner
- Institut für Theoretische und Angwandte Physik, Universität Stuttgart, D-70550 Stuttgart, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Euchner H, Yamada T, Schober H, Rols S, Mihalkovič M, Tamura R, Ishimasa T, de Boissieu M. Ordering and dynamics of the central tetrahedron in the 1/1 Zn6Sc periodic approximant to quasicrystal. J Phys Condens Matter 2012; 24:415403. [PMID: 22989777 DOI: 10.1088/0953-8984/24/41/415403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Periodic approximants to quasicrystals offer a unique opportunity to better understand the structure, physical properties and stabilizing mechanisms of their quasicrystal counterparts. We present a detailed study of the order-disorder phase transition occurring at about 160 K in the Zn(6)Sc cubic approximant to the icosahedral quasicrystal i-MgZnSc. This transition goes along with an anti-parallel ordering of the tetrahedra located at the centres of large atomic clusters, which are packed on a bcc lattice. Single crystal x-ray diffuse scattering shows that the tetrahedra display pre-transitional short range ordering above T(c) (Yamada et al 2012 in preparation). Using quasielastic neutron scattering (QENS) we clearly evidence this short range order to be dynamical in nature above T(c). The QENS data are consistent with a model of tetrahedra 'jumping' between almost equivalent positions, which is supported by molecular dynamics simulations. This demonstrates a unique dynamical flexibility of the Zn(6)Sc structure even at room temperature.
Collapse
Affiliation(s)
- Holger Euchner
- Institut für Theoretische und Angewandte Physik, Universität Stuttgart, Stuttgart, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
de Boissieu M, Yamada T, Euchner H, Gómez CP, Tamura R. Diffuse scattering and phason modes in the Zn–Sc binary icosahedral quasicrystal. Acta Crystallogr A 2012. [DOI: 10.1107/s0108767312098753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
23
|
Euchner H, Yamada T, Tamura R, Ishimasa T, Rols S, Schober H, Mihalkovic M, de Boissieu M. Tetrahedron dynamics in the i-ZnMgSc quasicrystal and its 1/1 periodic approximant Zn 6Sc. Acta Crystallogr A 2012. [DOI: 10.1107/s0108767312097371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
24
|
de Boissieu M, Euchner H, Yamada T, Rols S, Schober H, Tamura R, Mihalkovic M. Dynamics of the inner tetrahedron in the ZnSc 1/1 quasicrystal approximant: experiment and simulation. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311094712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
25
|
Yamada T, Euchner H, Gòmez CP, Tamura R, de Boissieu M. Diffuse scattering and phason modes in the Zn-Sc icosahedral quasicrystal. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311089549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
26
|
Yamada T, Gomez CP, Tamurab R, Euchner H, Yamamoto A, de Boissieu M. Diffuse scattering in the Zn 6Sc 1/1 cubic approximant. Acta Crystallogr A 2010. [DOI: 10.1107/s0108767310096674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
27
|
Abstract
Abstract
We present here simulation results on the dynamical structure factor of the C14 Laves Phase of MgZn2, the simplest of the Mg–(Al,Zn) Frank-Kasper alloy phases. The dynamical structure factor was determined in two ways. Firstly, the dynamical matrix was obtained in harmonic approximation from ab-initio forces. The dynamical structure factor can then be computed from the eigenvalues of the dynamical matrix. Alternatively, Molecular Dynamics simulations of a larger sample were used to measure the correlation function corresponding to the dynamical structure factor. Both results are compared to data from neutron scattering experiments. This comparison also includes the intensity distribution, which is a very sensitive test. We find that the dynamical structure factor determined with either method agrees reasonably well with the experiment. In particular, the intensity transfer from acoustic to optic phonon modes can be reproduced correctly. This shows that simulation studies can complement phonon dispersion measurements.
Collapse
Affiliation(s)
| | - Marc de Boissieu
- UMR CNRS 5614, ENSEEG-INPG-UJF, Laboratoire de Thermodynamique et Physico-Chimie M, St. Martin dHères Cedex, Frankreich
| | | | - Sonia Francoual
- Laboratoire de Thermodynamique et Physico-Chimie Métallurgique, UMR CNRS 5614, ENSEEG-INPG-UJF, St. Martin dHères Cedex, Frankreich
| | | | | | | | | |
Collapse
|