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Abrikosov, Igor A., Professor
Alternative names
Publications (10 of 196) Show all publications
Skripnyak, N., Ponomareva, A. V., Belov, M. P. & Abrikosov, I. A. (2018). Ab initio calculations of elastic properties of alloys with mechanical instability: Application to BCC Ti-V alloys. Materials & design, 140, 357-365
Open this publication in new window or tab >>Ab initio calculations of elastic properties of alloys with mechanical instability: Application to BCC Ti-V alloys
2018 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 140, p. 357-365Article in journal (Refereed) Published
Abstract [en]

Considering Ti-V alloys with the body-centered cubic crystal lattice, a system with mechanical instability for Tirich alloys, we calculate their elastic properties using Projector Augmented Wave method and the exact muffin tin orbital method in a complete interval of V concentrations. The substitutional disorder is modeled using the special quasi-random structures technique and the coherent potential approximation. The efficiency and accuracy of the simulation techniques is analyzed, and a strategy for efficient high-throughput calculations of elastic properties of disordered alloys is proposed. Dependences of the single crystal elastic moduli on V concentration and a set ofmechanical characteristics of polycrystalline alloys are presented and discussed. The effect of V content on themechanical stabilization of the bcc Ti-V alloys is investigated. In agreement with experiment, we find that titanium-rich alloys are mechanically unstable, however the alloys becomemechanically stablewith increasing content of V in the system. We observe a nonlinear dependence of the alloys Youngs moduli in a vicinity of the mechanical stabilization and suggest that this effect can be used to design alloys with low values of the elastic moduli. (C) 2017 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Efficient first-principal simulations; Elastic moduli; Substitutional disorder; Ti-V alloys; Mechanical stabilization
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:liu:diva-145445 (URN)10.1016/j.matdes.2017.11.071 (DOI)000424943900037 ()
Note

Funding Agencies|Ministry of Education and Science of the Russian Federation [K2-2016-013, 211]; Swedish Research Council [2015-04391]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]

Available from: 2018-03-23 Created: 2018-03-23 Last updated: 2018-04-19
Xia, C., Tal, A., Johansson, L., Olovsson, W., Abrikosov, I. & Virojanadara, C. (2018). Effects of rhenium on graphene grown on SiC(0001). Journal of Electron Spectroscopy and Related Phenomena, 222, 117-121
Open this publication in new window or tab >>Effects of rhenium on graphene grown on SiC(0001)
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2018 (English)In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 222, p. 117-121Article in journal (Refereed) Published
Abstract [en]

We study the effects of Rhenium (Re) deposited on epitaxial monolayer graphene grown on SiC(0001) and after subsequent annealing at different temperatures, by performing high resolution photoelectron spectroscopy (PES) and angle resolved photoelectron spectroscopy (ARPES). The graphene-Re system is found to be thermally stable. While no intercalation or chemical reaction of the Re is detected after deposition and subsequent annealing up to 1200 degrees C, a gradual decrease in the binding energy of the Re 4f doublet is observed. We propose that a larger mobility of the Re atoms with increasing annealing temperature and hopping of Re atoms between different defective sites on the graphene sample could induce this decrease of Re 4f binding energy. This is corroborated by first principles density functional theory (DFT) calculations of the Re core-level binding energy shift. No change in the doping or splitting of the initial monolayer graphene electronic band structure is observed after Re deposition and annealing up to 1200 degrees C, only a broadening of the bands. (C) 2017 Elsevier B.V. All rights reserved.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Rhenium; Graphene; Photoelectron spectroscopy; Core-level shift; Ab initio density functional theory
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-145152 (URN)10.1016/j.elspec.2017.07.006 (DOI)000423638100016 ()
Note

Funding Agencies|Knut and Alice Wallenberg Foundation [2012.0083]; Knut and Alice Wallenberg Foundation through CoTXS; Swedish Foundation or Strategic Research (SSF) program SRL Grant [10-0026]; Swedish Research Council (VR) [2015-04391]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [200900971]; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Swedish Research Council [621-2011-4252]

Available from: 2018-02-13 Created: 2018-02-13 Last updated: 2018-03-19Bibliographically approved
Bykov, M., Bykova, E., Koemets, E., Fedotenko, T., Aprilis, G., Glazyrin, K., . . . Dubrovinsky, L. (2018). High-Pressure Synthesis of a Nitrogen-Rich Inclusion Compound ReN8·xN2 with Conjugated Polymeric Nitrogen Chains. Angewandte Chemie International Edition, 57(29), 9048-9053
Open this publication in new window or tab >>High-Pressure Synthesis of a Nitrogen-Rich Inclusion Compound ReN8·xN2 with Conjugated Polymeric Nitrogen Chains
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2018 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 57, no 29, p. 9048-9053Article in journal (Refereed) Published
Abstract [en]

A nitrogen-rich compound, ReN(8)xN(2), was synthesized by a direct reaction between rhenium and nitrogen at high pressure and high temperature in a laser-heated diamond anvil cell. Single-crystal X-ray diffraction revealed that the crystal structure, which is based on the ReN8 framework, has rectangular-shaped channels that accommodate nitrogen molecules. Thus, despite a very high synthesis pressure, exceeding 100GPa, ReN(8)xN(2) is an inclusion compound. The amount of trapped nitrogen (x) depends on the synthesis conditions. The polydiazenediyl chains [-N=N-] that constitute the framework have not been previously observed in any compound. Abinitio calculations on ReN(8)xN(2) provide strong support for the experimental results and conclusions.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2018
Keywords
high-energy-density materials; high-pressure chemistry; nitrides; polymeric nitrogen; X-ray diffraction
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:liu:diva-149844 (URN)10.1002/anie.201805152 (DOI)000438195200045 ()29774981 (PubMedID)
Note

Funding Agencies|German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) [DU 954-8/1, DU 954-11/1]; Federal Ministry of Education and Research, Germany (BMBF) [5K16WC1]; DFG [FOR2125, FOR 2440]; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005, K2-2017-080]; Swedish Research Council (VR) [2015-04391]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; VINN Excellence Center Functional Nanoscale Materials (FunMat-2) Grant [2016-05156]

Available from: 2018-08-02 Created: 2018-08-02 Last updated: 2018-08-22
Ivády, V., Davidsson, J., Nguyen, T. S., Ohshima, T., Abrikosov, I. & Gali, A. (2017). Identification of Si-vacancy related room-temperature qubits in 4H silicon carbide. Physical Review B, 96(16), Article ID 161114.
Open this publication in new window or tab >>Identification of Si-vacancy related room-temperature qubits in 4H silicon carbide
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2017 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 96, no 16, article id 161114Article in journal (Refereed) Published
Abstract [en]

The identification of a microscopic configuration of point defects acting as quantum bits is a key step in the advance of quantum information processing and sensing. Among the numerous candidates, silicon-vacancy related centers in silicon carbide (SiC) have shown remarkable properties owing to their particular spin-3/2 ground and excited states. Although, these centers were observed decades ago, two competing models, the isolated negatively charged silicon vacancy and the complex of negatively charged silicon vacancy and neutral carbon vacancy [Phys. Rev. Lett. 115, 247602 (2015)], are still argued as an origin. By means of high-precision first-principles calculations and high-resolution electron spin resonance measurements, we here unambiguously identify the Si-vacancy related qubits in hexagonal SiC as isolated negatively charged silicon vacancies. Moreover, we identify the Si-vacancy qubit configurations that provide room-temperature optical readout.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2017
National Category
Other Physics Topics
Identifiers
urn:nbn:se:liu:diva-142978 (URN)10.1103/PhysRevB.96.161114 (DOI)000413848300001 ()
Note

Funding Agencies|Knut & Alice Wallenberg Foundation project Strong Field Physics and New States of Matter; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Swedish Research Council [VR 2016-04068]; Carl-Trygger Stiftelse for Vetenskaplig Forskning [CTS 15:339]; JSPS KAKENHI [A 17H01056]; Hungarian NKFIH Grant [NVKP_16-1-2016-0152958]

Available from: 2017-11-13 Created: 2017-11-13 Last updated: 2018-01-25Bibliographically approved
Wang, F., Abrikosov, I., Simak, S., Odén, M., Muecklich, F. & Tasnadi, F. (2016). Coherency effects on the mixing thermodynamics of cubic Ti1-xAlxN/TiN(001) multilayers. PHYSICAL REVIEW B, 93(17), 174201
Open this publication in new window or tab >>Coherency effects on the mixing thermodynamics of cubic Ti1-xAlxN/TiN(001) multilayers
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2016 (English)In: PHYSICAL REVIEW B, ISSN 2469-9950, Vol. 93, no 17, p. 174201-Article in journal (Refereed) Published
Abstract [en]

In this work, we discuss the mixing thermodynamics of cubic (B1) Ti1-xAlxN/TiN(001) multilayers. We show that interfacial effects suppress the mixing enthalpy compared to bulk Ti1-xAlxN. The strongest stabilization occurs for compositions in which the mixing enthalpy of bulk Ti1-xAlxN has its maximum. The effect is split into a strain and an interfacial (or chemical) contribution, and we show that both contributions are significant. An analysis of the local atomic structure reveals that the Ti atoms located in the interfacial layers relax significantly different from those in the other atomic layers of the multilayer. Considering the electronic structure of the studied system, we demonstrate that the lower Ti-site projected density of states at epsilon(F) in the Ti1-xAlxN/TiN multilayers compared to the corresponding monolithic bulk explains a decreased tendency toward decomposition.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-129166 (URN)10.1103/PhysRevB.93.174201 (DOI)000375990200003 ()
Note

Funding Agencies|Swedish Foundation for Strategic Research (SSF) project SRL [10-0026]; Erasmus Mundus Joint European Doctoral Programme DocMASE; Multiscale computational-design of novel hard nanostructure coatings; Swedish Research Council (VR) [2015-04391, 621-2012-4401, 2014-4750]; Grant of Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D. I. Mendeleev Fund Program [8.1.18.2015]; LiLi-NFM; Swedish Government Strategic Research Area Grant in Materials Science

Available from: 2016-06-13 Created: 2016-06-13 Last updated: 2018-02-09
Sangiovanni, D., Hellman, O., Alling, B. & Abrikosov, I. (2016). Efficient and accurate determination of lattice-vacancy diffusion coefficients via non equilibrium ab initio molecular dynamics. PHYSICAL REVIEW B, 93(9), 094305
Open this publication in new window or tab >>Efficient and accurate determination of lattice-vacancy diffusion coefficients via non equilibrium ab initio molecular dynamics
2016 (English)In: PHYSICAL REVIEW B, ISSN 2469-9950, Vol. 93, no 9, p. 094305-Article in journal (Refereed) Published
Abstract [en]

We revisit the color-diffusion algorithm [Aeberhard et al., Phys. Rev. Lett. 108, 095901 (2012)] in non equilibrium ab initio molecular dynamics (NE-AIMD) and propose a simple efficient approach for the estimation of monovacancy jump rates in crystalline solids at temperatures well below melting. Color-diffusion applied to monovacancy migration entails that one lattice atom (colored atom) is accelerated toward the neighboring defect site by an external constant force F. Considering bcc molybdenum between 1000 and 2800 K as a model system, NE-AIMD results show that the colored-atom jump rate k(NE) increases exponentially with the force intensity F, up to F values far beyond the linear-fitting regime employed previously. Using a simple model, we derive an analytical expression which reproduces the observed k(NE)(F) dependence on F. Equilibrium rates extrapolated by NE-AIMD results are in excellent agreement with those of unconstrained dynamics. The gain in computational efficiency achieved with our approach increases rapidly with decreasing temperatures and reaches a factor of 4 orders of magnitude at the lowest temperature considered in the present study.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-127268 (URN)10.1103/PhysRevB.93.094305 (DOI)000372711200003 ()
Note

Funding Agencies|Knut and Alice Wallenberg Foundation [2011.0094]; Swedish Research Council (VR) [621-2011-4417, 2015-04391, 637-2013-7296, 330-2014-336]; Linkoping Linnaeus Initiative LiLi-NFM [2008-6572]; Swedish Government Strategic Research Area Grant in Materials Science on Advanced Functional Materials [MatLiU 2009-00971]; Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D. I. Mendeleev Fund Program

Available from: 2016-04-20 Created: 2016-04-19 Last updated: 2019-06-28
Mozafari, E., Shulumba, N., Steneteg, P., Alling, B. & Abrikosov, I. A. (2016). Finite-temperature elastic constants of paramagnetic materials within the disordered local moment picture from ab initio molecular dynamics calculations. Physical Review B, 94(5), Article ID 054111.
Open this publication in new window or tab >>Finite-temperature elastic constants of paramagnetic materials within the disordered local moment picture from ab initio molecular dynamics calculations
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2016 (English)In: Physical Review B, ISSN 2469-9950, Vol. 94, no 5, article id 054111Article in journal (Refereed) Published
Abstract [en]

We present a theoretical scheme to calculate the elastic constants of magnetic materials in the high-temperature paramagnetic state. Our approach is based on a combination of disordered local moments picture and ab initio molecular dynamics (DLM-MD). Moreover, we investigate a possibility to enhance the efficiency of the simulations of elastic properties using the recently introduced method: symmetry imposed force constant temperature-dependent effective potential (SIFC-TDEP). We have chosen cubic paramagnetic CrN as a model system. This is done due to its technological importance and its demonstrated strong coupling between magnetic and lattice degrees of freedom. We have studied the temperature-dependent single-crystal and polycrystalline elastic constants of paramagentic CrN up to 1200 K. The obtained results at T = 300 K agree well with the experimental values of polycrystalline elastic constants as well as the Poisson ratio at room temperature. We observe that the Young’s modulus is strongly dependent on temperature, decreasing by 14% from T = 300 K to 1200 K. In addition we have studied the elastic anisotropy of CrN as a function of temperature and we observe that CrN becomes substantially more isotropic as the temperature increases. We demonstrate that the use of Birch law may lead to substantial errors for calculations of temperature induced changes of elastic moduli. The proposed methodology can be used for accurate predictions of mechanical properties of magnetic materials at temperatures above their magnetic order-disorder phase transition.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
National Category
Physical Sciences Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-130779 (URN)10.1103/PhysRevB.94.054111 (DOI)000381475300002 ()
Note

Funding agencies. Swedish Research Council (VR) [621-2011-4426, 621-2011-4417, 330-2014-6336]; Swedish Foundation for Strategic Research (SSF) program SRL [10-0026]; Ministry of Education and Science of the Russian Federation [K2-2016-013, 14.Y26.31.0005]; Marie Sklodowska

Available from: 2016-08-23 Created: 2016-08-23 Last updated: 2016-09-26Bibliographically approved
Shulumba, N., Raza, Z., Hellman, O., Janzén, E., Abrikosov, I. & Odén, M. (2016). Impact of anharmonic effects on the phase stability, thermal transport, and electronic properties of AlN. Physical Review B, 94(10), Article ID 104305.
Open this publication in new window or tab >>Impact of anharmonic effects on the phase stability, thermal transport, and electronic properties of AlN
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2016 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 94, no 10, article id 104305Article in journal (Refereed) Published
Abstract [en]

Wurtzite aluminium nitride is a technologically important wide band gap semiconductor with an unusually high thermal conductivity, used in optical applications and as a heatsink substrate. Many of its properties depend on an accurate description of its lattice dynamics, which have thus far only been captured in the quasiharmonic approximation. In this work, we demonstrate that anharmonicity has a considerable impact on its phase stability and transport properties, since anharmonicity is much stronger in the rocksalt phase. We compute a pressure-temperature phase diagram of AlN, demonstrating that the rocksalt phase is stabilised by increasing temperature, with respect to the wurtzite phase. We demonstrate that including anharmonicity, we can recover the thermal conductivity of the wurtzite phase (320 Wm−1K−1 under ambient conditions), and compute the hitherto unknown thermal conductivity of the rocksalt phase (96 Wm−1K−1). We also show that the electronic band gap decreases with temperature. These findings provide further evidence that anharmonic effects cannot be ignored in high temperature applications.

National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-122955 (URN)10.1103/PhysRevB.94.104305 (DOI)000384061100003 ()
Note

Funding agencies; Swedish Research Council (VR programs) [2015-04391, 621-2012-4401]; Swedish Foundation for Strategic Research (SSF program) [SRL10-0026]; VINNOVA [M-Era.net Project] [2013-02355 (MC2)]; Swedish Research Council VR program [637-2013-7296]; Swedish Foundati

Available from: 2015-11-30 Created: 2015-11-30 Last updated: 2017-12-01Bibliographically approved
Potapkin, V., Dubrovinsky, L., Sergueev, I., Ekholm, M., Kantor, I., Bessas, D., . . . Abrikosov, I. (2016). Magnetic interactions in NiO at ultrahigh pressure. PHYSICAL REVIEW B, 93(20), 201110
Open this publication in new window or tab >>Magnetic interactions in NiO at ultrahigh pressure
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2016 (English)In: PHYSICAL REVIEW B, ISSN 2469-9950, Vol. 93, no 20, p. 201110-Article in journal (Refereed) Published
Abstract [en]

Magnetic properties of NiO have been studied in the multimegabar pressure range by nuclear forward scattering of synchrotron radiation using the 67.4 keV Mossbauer transition of Ni-61. The observed magnetic hyperfine splitting confirms the antiferromagnetic state of NiO up to 280 GPa, the highest pressure where magnetism has been observed so far, in any material. Remarkably, the hyperfine field increases from 8.47 T at ambient pressure to similar to 24 T at the highest pressure, ruling out the possibility of a magnetic collapse. A joint x-ray diffraction and extended x-ray-absorption fine structure investigation reveals that NiO remains in a distorted sodium chloride structure in the entire studied pressure range. Ab initio calculations support the experimental observations, and further indicate a complete absence of Mott transition in NiO up to at least 280 GPa.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-129492 (URN)10.1103/PhysRevB.93.201110 (DOI)000376638400001 ()
Note

Funding Agencies|National Science Foundation-Earth Sciences [EAR-1128799]; Department of Energy-GeoSciences [DE-FG02-94ER14466]; DOE Office of Science [DE-AC02-06CH11357]; Helmholtz Association; Materials Sciences and Engineering Division, Office of Basic Energy Sciences, U.S. Department of Energy; Swedish Government Strategic Research Area Grants Swedish e-Science Research Center (SeRC) and in Materials Science on Functional Materials at Linkoping University [2009 00971]; Knut and Alice Wallenbergs Foundation project Strong Field Physics and New States of Matter; Swedish Foundation for Strategic Research program SRL Grant [10-0026]; Swedish Research Council (VR) [2015-04391]; Grant of Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Tomsk State University Academic D.I. Mendeleev Fund Program

Available from: 2016-06-20 Created: 2016-06-20 Last updated: 2018-08-29
Dahlqvist, M., Ingason, A. S., Alling, B., Magnus, F., Thore, A., Petruhins, A., . . . Rosén, J. (2016). Magnetically driven anisotropic structural changes in the atomic laminate Mn2GaC. Physical Review B, 93(1), 014410
Open this publication in new window or tab >>Magnetically driven anisotropic structural changes in the atomic laminate Mn2GaC
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2016 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 93, no 1, p. 014410-Article in journal (Refereed) Published
Abstract [en]

Inherently layered magnetic materials, such as magnetic M(n+1)AX(n) (MAX) phases, offer an intriguing perspective for use in spintronics applications and as ideal model systems for fundamental studies of complex magnetic phenomena. The MAX phase composition M(n+1)AX(n) consists of M(n+1)AX(n) blocks separated by atomically thin A-layers where M is a transition metal, A an A-group element, X refers to carbon and/or nitrogen, and n is typically 1, 2, or 3. Here, we show that the recently discovered magnetic Mn2GaC MAX phase displays structural changes linked to the magnetic anisotropy, and a rich magnetic phase diagram which can be manipulated through temperature and magnetic field. Using first-principles calculations and Monte Carlo simulations, an essentially one-dimensional (1D) interlayer plethora of two-dimensioanl (2D) Mn-C-Mn trilayers with robust intralayer ferromagnetic spin coupling was revealed. The complex transitions between them were observed to induce magnetically driven anisotropic structural changes. The magnetic behavior as well as structural changes dependent on the temperature and applied magnetic field are explained by the large number of low energy, i.e., close to degenerate, collinear and noncollinear spin configurations that become accessible to the system with a change in volume. These results indicate that the magnetic state can be directly controlled by an applied pressure or through the introduction of stress and show promise for the use of Mn2GaC MAX phases in future magnetoelectric and magnetocaloric applications.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2016
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-124463 (URN)10.1103/PhysRevB.93.014410 (DOI)000367779000005 ()
Note

Funding Agencies|European Research Council under the European Communities Seventh Framework Programme (FP7)/ERC Grant [258509]; Swedish Research Council (VR) [642-2013-8020, 621-2011-4417]; KAW Fellowship program; SSF synergy grant FUNCASE; VR Grant [621-2011-4426]; Russian Federation Ministry for Science and Education [14.Y26.31.0005]; Tomsk State University Academic D. I. Mendeleev Fund Program

Available from: 2016-02-02 Created: 2016-02-01 Last updated: 2017-11-30
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