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Jami P, Chaudhuri P, Dasgupta C, Ghosal A. Effect of disorder on phases across two-dimensional thermal melting. Phys Rev E 2024; 109:L062101. [PMID: 39021015 DOI: 10.1103/physreve.109.l062101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 04/11/2024] [Indexed: 07/20/2024]
Abstract
We study melting in a two-dimensional system of classical particles with Gaussian-core interactions in disordered environments. The pure system validates the conventional two-step melting with a hexatic phase intervening between the solid and the liquid. This picture is modified in the presence of pinning impurities. A random distribution of pinning centers forces a hexaticlike low-temperature phase that transits into a liquid at a single melting temperature T_{m}^{RP}. In contrast, pinning centers located at randomly chosen sites of a perfect crystal anchor a solid at low temperatures which undergoes a direct transition to the liquid at T_{m}^{CP}. Thus, the two-step melting is lost in either case of disorder. We discuss the characteristics of melting depending on the nature of the impurities.
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Fomin YD, Tsiok EN, Ryzhov VN. The Structure of a System of Smoothed Collapsing Spheres under Strong Confinement. COLLOID JOURNAL 2022. [DOI: 10.1134/s1061933x22700168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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3
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Tsiok EN, Fomin YD, Gaiduk EA, Tareyeva EE, Ryzhov VN, Libet PA, Dmitryuk NA, Kryuchkov NP, Yurchenko SO. The role of attraction in the phase diagrams and melting scenarios of generalized 2D Lennard-Jones systems. J Chem Phys 2022; 156:114703. [DOI: 10.1063/5.0075479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Monolayer and two-dimensional (2D) systems exhibit rich phase behavior, compared with 3D systems, in particular, due to the hexatic phase playing a central role in melting scenarios. The attraction range is known to affect critical gas–liquid behavior (liquid–liquid in protein and colloidal systems), but the effect of attraction on melting in 2D systems remains unstudied systematically. Here, we have revealed how the attraction range affects the phase diagrams and melting scenarios in a 2D system. Using molecular dynamics simulations, we have considered the generalized Lennard-Jones system with a fixed repulsion branch and different power indices of attraction from long-range dipolar to short-range sticky-sphere-like. A drop in the attraction range has been found to reduce the temperature of the gas–liquid critical point, bringing it closer to the gas–liquid–solid triple point. At high temperatures, attraction does not affect the melting scenario that proceeds through the cascade of solid–hexatic (Berezinskii–Kosterlitz–Thouless) and hexatic–liquid (first-order) phase transitions. In the case of dipolar attraction, we have observed two triple points inherent in a 2D system: hexatic–liquid–gas and crystal–hexatic–gas, the temperature of the crystal–hexatic–gas triple point is below the hexatic–liquid–gas triple point. This observation may have far-reaching consequences for future studies, since phase diagrams determine possible routes of self-assembly in molecular, protein, and colloidal systems, whereas the attraction range can be adjusted with complex solvents and external electric or magnetic fields. The results obtained may be widely used in condensed matter, chemical physics, materials science, and soft matter.
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Affiliation(s)
- Elena N. Tsiok
- Institute of High Pressure Physics RAS, Kaluzhskoe Shosse, 14, Troitsk, Moscow 108840, Russia
| | - Yuri D. Fomin
- Institute of High Pressure Physics RAS, Kaluzhskoe Shosse, 14, Troitsk, Moscow 108840, Russia
| | - Eugene A. Gaiduk
- Institute of High Pressure Physics RAS, Kaluzhskoe Shosse, 14, Troitsk, Moscow 108840, Russia
| | - Elena E. Tareyeva
- Institute of High Pressure Physics RAS, Kaluzhskoe Shosse, 14, Troitsk, Moscow 108840, Russia
| | - Valentin N. Ryzhov
- Institute of High Pressure Physics RAS, Kaluzhskoe Shosse, 14, Troitsk, Moscow 108840, Russia
| | - Pavel A. Libet
- Institute of High Pressure Physics RAS, Kaluzhskoe Shosse, 14, Troitsk, Moscow 108840, Russia
- Bauman Moscow State Technical University, 2nd Baumanskaya Street 5, 105005 Moscow, Russia
| | - Nikita A. Dmitryuk
- Bauman Moscow State Technical University, 2nd Baumanskaya Street 5, 105005 Moscow, Russia
| | - Nikita P. Kryuchkov
- Bauman Moscow State Technical University, 2nd Baumanskaya Street 5, 105005 Moscow, Russia
| | - Stanislav O. Yurchenko
- Bauman Moscow State Technical University, 2nd Baumanskaya Street 5, 105005 Moscow, Russia
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4
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Padilla LA, León-Islas AA, Funkhouser J, Armas-Pérez JC, Ramírez-Hernández A. Dynamics and phase behavior of two-dimensional size-asymmetric binary mixtures of core-softened colloids. J Chem Phys 2021; 155:214901. [PMID: 34879672 DOI: 10.1063/5.0067449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The self-assembly of binary colloidal mixtures provides a bottom-up approach to create novel functional materials. To elucidate the effect of composition, temperature, and pressure on the self-assembly behavior of size-asymmetric mixtures, we performed extensive dynamics simulations of a simple model of polymer-grafted colloids. We have used a core-softened interaction potential and extended it to represent attractive interactions between unlike colloids and repulsions between like colloids. Our study focused on size-asymmetric mixtures where the ratio between the sizes of the colloidal cores was fixed at σBσA=0.5. We have performed extensive simulations in the isothermal-isobaric and canonical (NVT) ensembles to elucidate the phase behavior and dynamics of mixtures with different stoichiometric ratios. Our simulation results uncovered a rich phase behavior, including the formation of hierarchical structures with many potential applications. For compositions where small colloids are the majority, sublattice melting occurs for a wide range of densities. Under these conditions, large colloids form a well-defined lattice, whereas small colloids can diffuse through the system. As the temperature is decreased, the small colloids localize, akin to a metal-insulator transition, with the small colloids playing a role similar to electrons. Our results are summarized in terms of phase diagrams.
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Affiliation(s)
- Luis A Padilla
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, San Antonio, Texas 78249, USA
| | - Andres A León-Islas
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, San Antonio, Texas 78249, USA
| | - Jesse Funkhouser
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, San Antonio, Texas 78249, USA
| | - Julio C Armas-Pérez
- División de Ciencias e Ingenierías, Universidad de Guanajuato, Loma del Bosque 103, Colonia Lomas del Campestre, CP 37150 León, Guanajuato, Mexico
| | - Abelardo Ramírez-Hernández
- Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, San Antonio, Texas 78249, USA
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Altvater MA, Tilak N, Rao S, Li G, Won CJ, Cheong SW, Andrei EY. Charge Density Wave Vortex Lattice Observed in Graphene-Passivated 1T-TaS 2 by Ambient Scanning Tunneling Microscopy. NANO LETTERS 2021; 21:6132-6138. [PMID: 34231367 DOI: 10.1021/acs.nanolett.1c01655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The nearly commensurate charge density wave (CDW) excitations native to the transition-metal dichalcogenide crystal, 1T-TaS2, under ambient conditions are revealed by scanning tunneling microscopy (STM) and spectroscopy (STS) measurements of a graphene/TaS2 heterostructure. Surface potential measurements show that the graphene passivation layer prevents oxidation of the air-sensitive 1T-TaS2 surface. The graphene protective layer does not however interfere with probing the native electronic properties of 1T-TaS2 by STM/STS, which revealed that nearly commensurate CDW hosts an array of vortex-like topological defects. We find that these topological defects organize themselves to form a lattice with quasi-long-range order, analogous to the vortex Bragg glass in type-II superconductors but accessible in ambient conditions.
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Affiliation(s)
- Michael A Altvater
- Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Nikhil Tilak
- Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Skandaprasad Rao
- Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Guohong Li
- Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Choong-Jae Won
- Laboratory for Pohang Emergent Materials, Pohang Accelerator Laboratory and Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Sang-Wook Cheong
- Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
- Laboratory for Pohang Emergent Materials, Pohang Accelerator Laboratory and Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang 790-784, Korea
- Center for Quantum Materials Synthesis, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Eva Y Andrei
- Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
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6
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Tsiok EN, Fomin YD, Gaiduk EA, Ryzhov VN. Structural transition in two-dimensional Hertzian spheres in the presence of random pinning. Phys Rev E 2021; 103:062612. [PMID: 34271643 DOI: 10.1103/physreve.103.062612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/03/2021] [Indexed: 11/07/2022]
Abstract
Using molecular dynamics simulation we have investigated the influence of random pinning on the phase diagram and melting scenarios of a two-dimensional system with the Hertz potential for α=5/2. It has been shown that random pinning can cardinally change the mechanism of first-order transition between the different crystalline phases (triangular and square) by virtue of generating hexatic and tetratic phases: a triangular crystal to hexatic transition is of the continuous Berezinskii-Kosterlitz-Thouless (BKT) type, a hexatic to tetratic transition is of first order, and finally, there is a continuous BKT-type transition from tetratic to the square crystal.
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Affiliation(s)
- E N Tsiok
- Institute of High Pressure Physics RAS, Kaluzhskoe shosse, 14, Troitsk, 108840 Moscow, Russia
| | - Yu D Fomin
- Institute of High Pressure Physics RAS, Kaluzhskoe shosse, 14, Troitsk, 108840 Moscow, Russia
| | - E A Gaiduk
- Institute of High Pressure Physics RAS, Kaluzhskoe shosse, 14, Troitsk, 108840 Moscow, Russia
| | - V N Ryzhov
- Institute of High Pressure Physics RAS, Kaluzhskoe shosse, 14, Troitsk, 108840 Moscow, Russia
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7
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Fomin YD. Between two and three dimensions: Crystal structures in a slit pore. J Colloid Interface Sci 2020; 580:135-145. [PMID: 32683112 DOI: 10.1016/j.jcis.2020.06.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 10/23/2022]
Abstract
The structure of a simple monatomic system in a slit pore has been studied by means of the molecular dynamics simulation. Nowadays, it is supposed that the structure of crystals in a narrow pore (narrower than approximately eight atomic diameters) should be described as a set of two-dimensional layers with either triangular, or square symmetry. In addition, a buckled phase can appear with particles located in zigzag way around a plane. It is shown that all these structures can be considered as cuts of FCC or HCP structures.
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Affiliation(s)
- Yu D Fomin
- Vereshchagin Institute of High Pressure Physics, Russian Academy of Sciences, Kaluzhskoe shosse, 14, Troitsk, Moscow 108840 Russia; Moscow Institute of Physics and Technology (National Research University), 9 Institutskiy Lane, Dolgoprudny, Moscow region 141701, Russia.
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8
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H A, Chaudhuri P. Dense hard disk ordering: influence of bidispersity and quenched disorder. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:414001. [PMID: 32521523 DOI: 10.1088/1361-648x/ab9b52] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
Using Monte Carlo simulations, the impact on structural ordering in two-dimensional systems via the interplay of size bidispersity and quenched disorder in the form of an externally applied spatially random potential, is studied for a system of hard disks. By scanning across a wide range of dense packing fractions, size ratios and roughness of the applied potential, the phase diagram is constructed, which demonstrates that both quenched and size disorders shift the onset of translational order to higher packings, while maintaining the presence of the intermediate hexatic phase. At larger disorder strengths, the signatures of structural order are absent within the range of investigated packing fractions. Further, the dynamics with increasing potential strength is analysed for the mono-component system to obtain a spatio-temporal description of the melting process. Finally, the influence of the externally rough field on the Mermin-Wagner fluctuations, characteristic to two-dimensional systems, is investigated.
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Affiliation(s)
- Arjun H
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai-600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Pinaki Chaudhuri
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai-600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
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9
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Tsiok EN, Gaiduk EA, Fomin YD, Ryzhov VN. Melting scenarios of two-dimensional Hertzian spheres with a single triangular lattice. SOFT MATTER 2020; 16:3962-3972. [PMID: 32249869 DOI: 10.1039/c9sm02262g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We present a molecular dynamics simulation study of the phase diagram and melting scenarios of two-dimensional Hertzian spheres with exponent 7/2. We have found multiple re-entrant melting of a single crystal with a triangular lattice in a wide range of densities from 0.5 to 10.0. Depending on the position on the phase diagram, the triangular crystal has been shown to melt through both two-stage melting with a first-order hexatic-isotropic liquid transition and a continuous solid-hexatic transition as well as in accordance with the Berezinskii-Kosterlitz-Thouless-Halperin-Nelson-Young (BKTHNY) scenario (two continuous transitions with an intermediate hexatic phase). We studied the behavior of heat capacity and have shown that despite two-stage melting, the heat capacity has one peak which seems to correspond to a solid-hexatic transition.
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Affiliation(s)
- E N Tsiok
- Vereshchagin Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk 108840, Moscow, Russia.
| | - E A Gaiduk
- Vereshchagin Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk 108840, Moscow, Russia.
| | - Yu D Fomin
- Vereshchagin Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk 108840, Moscow, Russia. and Moscow Institute of Physics and Technology, 9 Institutskiy Lane, Dolgoprudny City, Moscow Region, Russia
| | - V N Ryzhov
- Vereshchagin Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk 108840, Moscow, Russia.
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10
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Fomin YD, Ryzhov VN, Tsiok EN. The influence of long-range interaction on the structure of a two-dimensional multi scale potential system. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:315103. [PMID: 31039557 DOI: 10.1088/1361-648x/ab1df6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present the results of a computer simulation study of a finite temperature phase diagram of two-dimensional and quasi two-dimensional core-softened systems both taking into account long-range Coulomb-like forces and ignoring them. The system structure was determined from analysis of the behavior of radial distribution functions, order parameters and number of nearest neighbors. The system has been shown to have a large number of different phases. We have found that long-range forces substantially affected the structure and the melting point of the system at low and moderate densities, while at high densities the effect of long-range forces was negligible.
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11
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Gaiduk EA, Fomin Y, Tsiok EN, Ryzhov VN. The influence of random pinning on the melting scenario of two-dimensional soft-disk systems. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1607917] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- E. A. Gaiduk
- Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russia
| | - Yu.D. Fomin
- Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russia
| | - E. N. Tsiok
- Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russia
| | - V. N. Ryzhov
- Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russia
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12
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Su R, Guan Q, Cai W, Yang W, Xu Q, Guo Y, Zhang L, Fei L, Xu M. Multi-color carbon dots for white light-emitting diodes. RSC Adv 2019; 9:9700-9708. [PMID: 35520699 PMCID: PMC9062395 DOI: 10.1039/c8ra09868a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 03/15/2019] [Indexed: 01/12/2023] Open
Abstract
Single metal-doped CDs with color-tunable properties have been successful synthesized by regulating the precursor molar ratios.
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Affiliation(s)
- Rigu Su
- State Key Laboratory of Heavy Oil Processing
- China University of Petroleum (Beijing)
- China
| | - Qingwen Guan
- State Key Laboratory of Heavy Oil Processing
- China University of Petroleum (Beijing)
- China
| | - Wei Cai
- State Key Laboratory of Heavy Oil Processing
- China University of Petroleum (Beijing)
- China
| | - Wenjing Yang
- State Key Laboratory of Heavy Oil Processing
- China University of Petroleum (Beijing)
- China
| | - Quan Xu
- State Key Laboratory of Heavy Oil Processing
- China University of Petroleum (Beijing)
- China
| | - Yongjian Guo
- College of Energy
- Beijing University of Chemical Technology
- Beijing
- China
| | - Lipeng Zhang
- College of Energy
- Beijing University of Chemical Technology
- Beijing
- China
| | - Ling Fei
- Chemical Engineering Department
- University of Louisiana at Lafayette
- Lafayette
- USA
| | - Meng Xu
- Department of Orthopedics
- General Hospital of Chinese People's Liberation Army
- Beijing 100853
- China
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13
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Fomin YD, Gaiduk EA, Tsiok EN, Ryzhov VN. The phase diagram and melting scenarios of two-dimensional Hertzian spheres. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1464676] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Yu. D. Fomin
- Institute for High Pressure Physics RAS, Moscow, Russia
| | - E. A. Gaiduk
- Institute for High Pressure Physics RAS, Moscow, Russia
| | - E. N. Tsiok
- Institute for High Pressure Physics RAS, Moscow, Russia
| | - V. N. Ryzhov
- Institute for High Pressure Physics RAS, Moscow, Russia
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14
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Kryuchkov NP, Yurchenko SO, Fomin YD, Tsiok EN, Ryzhov VN. Complex crystalline structures in a two-dimensional core-softened system. SOFT MATTER 2018; 14:2152-2162. [PMID: 29488995 DOI: 10.1039/c7sm02429k] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A transition from a square to a hexagonal lattice is studied in a 2D system of particles interacting via a core-softened potential. Due to the presence of two length scales of repulsion, different local configurations with four, five, and six neighbors are possible, leading to the formation of complex crystals. The previously proposed interpolation method is generalized to calculate pair correlations in crystals whose unit cell consists of more than one particle. The high efficiency of the method is illustrated using a snub square lattice as a representative example. Molecular dynamics simulations show that the snub square lattice is broken upon heating, generating a high-density quasicrystalline phase with 12-fold symmetry (HD12 phase). A simple theoretical model is proposed to explain the physical mechanism responsible for this phenomenon: with an increase in the density (from square to hexagonal phases), the concentrations of different local configurations randomly realized through a plane tiling change, which minimizes the energy of the system. The calculated phase diagram in the intermediate density range justifies the existence of the HD12 phase and demonstrates a cascade of first-order transitions "square - HD12 - hexagonal" solid phases with increasing density. The results allow us to better understand the physical mechanisms responsible for the formation of quasicrystals, and, therefore, should be of interest for broad community in materials science and soft matter.
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Affiliation(s)
- Nikita P Kryuchkov
- Bauman Moscow State Technical University, 2nd Baumanskaya Street 5, 105005 Moscow, Russia.
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15
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Sándor C, Libál A, Reichhardt C, Olson Reichhardt CJ. Dewetting and spreading transitions for active matter on random pinning substrates. J Chem Phys 2017; 146:204903. [PMID: 28571342 DOI: 10.1063/1.4983344] [Citation(s) in RCA: 12] [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 show that sterically interacting self-propelled disks in the presence of random pinning substrates exhibit transitions among a variety of different states. In particular, from a phase separated cluster state, the disks can spread out and homogeneously cover the substrate in what can be viewed as an example of an active matter wetting transition. We map the location of this transition as a function of activity, disk density, and substrate strength, and we also identify other phases including a cluster state, coexistence between a cluster and a labyrinth wetted phase, and a pinned liquid. Convenient measures of these phases include the cluster size, which dips at the wetting-dewetting transition, and the fraction of sixfold coordinated particles, which drops when dewetting occurs.
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Affiliation(s)
- Cs Sándor
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Libál
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C Reichhardt
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C J Olson Reichhardt
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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16
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Herrera-Velarde S, Pérez-Angel G, Castañeda-Priego R. One-dimensional Gaussian-core fluid: ordering and crossover from normal diffusion to single-file dynamics. SOFT MATTER 2016; 12:9047-9057. [PMID: 27774539 DOI: 10.1039/c6sm01558a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The peculiarity of a bounded pair potential in combination with strong confinement brings some quite interesting new phenomenology in the structure and dynamics of one-dimensional colloidal systems. Such behaviour is atypical in comparison with colloidal systems interacting with potentials that diverge at the origin. In this contribution, by means of molecular dynamics simulations, a confined one-dimensional model of particles interacting via a Gaussian-core pair potential is studied. We explore the effects of confinement, density and temperature on the structural and dynamical correlation functions. Our findings indicate that the static and dynamic liquid-state anomalies already reported in open systems are also present in this 1D model system. Using the radial distribution function and the static structure factor to characterise the spatial ordering, it is observed that the system remains fluid at all densities. However, when the reduced temperature is above 0.03, it displays typical features of a liquid regime, i.e., there exist short-range spatial correlations among particles. In contrast, at lower temperatures and densities, where the particle-particle interaction dominates, the system behaves structurally and dynamically similar to a hard-core repulsive system. In such a region, interestingly, there is a crossover from a liquid to a solid-like regime. At any given temperature, the system undergoes a sort of reentrant structural behaviour as the density increases. At either high densities or temperatures, particle correlations vanish, thus, the system exhibits structural and dynamical properties similar to those of an ideal gas. To examine a possible correlation between the structural anomalies and the diffusive behaviour, the mean-square displacement and the self-intermediate scattering function are also computed. From these observables, we establish the thermodynamic phase-space points where the dynamical behaviour is non-monotonic. In conjunction with the observed anomalous diffusion, we have found a dynamical crossover from single-file diffusion, which is characteristic of one-dimensional systems with a well-defined hard-core, to the ordinary Fickian diffusion present in open systems.
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Affiliation(s)
- Salvador Herrera-Velarde
- Subdirección de Postgrado e Investigación, Instituto Tecnológico Superior de Xalapa, Sección 5A Reserva Territorial s/n, 91096, Xalapa, Veracruz, Mexico
| | - Gabriel Pérez-Angel
- Departamento de Física Aplicada, Cinvestav, Unidad Mérida, Apartado Postal 73 Cordemex, 97310, Mérida, Yucatán, Mexico
| | - Ramón Castañeda-Priego
- División de Ciencias e Ingenierías, Campus León, Universidad de Guanajuato, Loma del Bosque 103, Lomas del Campestre, 37150 León, Guanajuato, Mexico.
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