Department of Computational Physics of Complex Systems

Research

Head: Prof. Dr. habil. Krzysztof Witold Wojciechowski

Research goals

Investigations of counterintuitive phenomena, their description and explanation. In particular:

  • studies of models and materials exhibiting anomalous properties (e.g. negative Poisson's ratio, negative thermal expansion, and negative mechanical compliance - local or directional) or extreme properties (e.g. containing instable inclusions),
  • studies of the influence of various microscopic factors on macroscopic properties of the systems under consideration,
  • the identification of the phenomena and mechanisms behind the specific properties of matter that offer the possibility of practical applications.

Research profile

The research concerns micro- and macroscopic models of complex systems in the context of their extraordinary physical properties: structural, dynamic and thermodynamic. Our studies concentrate on the so-called auxetics, i.e. systems exhibiting anomalous (negative) Poisson's ratio, as well as on materials with instable inclusions, systems exhibiting negative thermal expansion and magneto-elastic systems. Beside some theoretical methods, various computer simulation methods and numerical techniques are used in the department, e.g., molecular dynamics, Monte-Carlo, mesh methods (finite element method) and meshless methods (fundamental solutions method).

Research projects

  • Project of the Polish National Center for Science: Computer modeling of auxetic foams (2013-2017, project leader: MSc. Eng. A.A.Pozniak, project supervisor: prof. Dr. Habil. K.W. Wojciechowski)
  • Projects of the Ministry of Science and Higher Education:
    1. Influence of the particles' size polydispersity on the elastic properties of classical model systems (2010-2013, project leader Dr. Habil. K.W. Tretiakov)
    2. Influence of the particles' size polydispersity on the elastic properties of selected molecular model systems (2007-2009, project leader: Prof. Dr. Habil. K.W. Wojciechowski, PhD student: J.W. Narojczyk)

Scientific Achievements

  • Microscopic studies, light transmission, dielectric and Hyper-Rayleigh scattering for two derivatives of bipiromidine showed high variety of physicochemical properties for both compounds. It has been discovered that both compounds exhibit liquid crystal properties in a certain range of temperatures. Besides strong fluorescence and two-photon absorption, these materials exhibit second-harmonic generation while subjected to laser illumination [S. van Cleuvenbergen, P. Kedziora, et al., Angew. Chem. Int. Ed. 56, 9546-9550 (2017)].
  • Time evolution of magnetic domains in magnetic auxetics with Ising interactions (where magnetic interaction depends on the lattice constant) were studied by computer simulations. It has been shown that mechanical deformation of the structure impacts on the domains evolution and the rate of the domains increase does not fulfill the power dependence related to Ising model with fixed lattice constant. It has been also shown that by altering the rate of mechanical deformation for the studied model, one can control the rate of the magnetic domains increase and, in the consequence, magnetic properties of the system. This may be of significance for certain practical applications [K.K. Dudek, et al. Phys. Stat. Solidi RRL 11 (8) 1700122 (2017)].
  • Selected structures of planar composites with periodic elliptical inclusions have been studied by computer simulations using finite element method. It has been shown that introducing non-auxetic macroinclusions in a non-auxetic matrix one can obtain an auxetic composite with high Young's modulus [A.A. Pozniak, K.W. Wojciechowski, J.N. Grima, L. Mizzi, Composites Part B 94, 379-388 (2016)].
  • With the use of high scale computer simulations (1 million CPU hours) it has been shown how to obtain the thinest auxetic yet proposed, from a graphene sheet. The mechanism behind the auxetic properties has been explained [J.N. Grima et al., Adv. Mater. 27, 1455 (2015)].
  • A novel, effective method for calculations of elastic constants for systems with long range inter-particle interactions has been proposed and tested for Lennard-Jones interactions [K.V. Tretiakov, K.W. Wojciechowski, Computer Phys. Commun. 189, 77 (2015)].
  • The structure and the properties of thin smectic layers placed in water has been studied using McMilan mean field method. It has been concluded that the transition of molecules from smectic A phase to an isotropic phase, commonly referred to as "melting", starts from the center of the system and moves towards the surfaces [I. Śliwa, A.V. Zakharov, J. Chem. Phys. 141, 194706 (2014)].
  • It has been shown that in the systems which are far from thermodynamic equilibrium, the nature favors the realization of states of lower energy dissipation. States with higher energy dissipation are also possible but less likely to occur [K.V. Tretiakov et al., Angewandte Chemie Intern. Ed. 52, 10304 (2013)].
  • By finite element methods it has been shown that after uniform compression and the removal of internal tensions the planar model foams spontaneously transfer into the auxetic state (their Poisson's ratio becomes negative). This means that methods for the foam auxetization used to date, are the special case of a general strategy [A.A. Poźniak et al., Smart Mater. Struct. 22, 084009 (2013)].
  • It has been shown that Poisson's ratio of two-dimensional system of polydisperse hard discs tends to +1 in the high pressure limit, for any non-zero polydispersity. This implies that Poisson's ratio is not continuous in this limit, when the polydispersity tends to zero [K.V. Tretiakov, K.W. Wojciechowski, J. Chem. Phys. 136, 204506 (2012)].
  • It has been shown that carbon nanotube heterojunctions are able to filter specific vibration modes, what can be useful in construction of novel stress nano-sensors or vibration filters [F. Scarpa et al., Nanotechnology 22, 465501 (2011)].
  • It has been shown that below a certain critical value of the Poisson's ratio, auxetic systems can exhibit locally negative mechanical compliance. This encourages one for applying auxetics as nano inclusions to produce materials with extreme mechanical properties (hardness, dumping, etc.) [A.A. Poźniak et al., Rev. Adv. Mater. Sci. 23,169 (2010)].
  • The propagation of soliton waves in auxetic plates has been studied. The results can be helpful in a non-destructive analysis of materials (especially composites) with the use of soliton impulses that are significantly less suppressed compared to harmonic vibrations P. Kolat et al., J. Non-Cryst. Solids 356, 2001 (2010)].
  • It has been shown that: (i) particle size polydispersity leads typically to an increase of the Poisson's ratio, which (ii) can be significantly lower for anisotropic systems than for isotropic systems. certain mechanisms leading to a decrease of Poisson's ratio has been identified [J.W. Narojczyk, PhD Thesis (2009)].
  • The measurements of nonlinear dielectric effect relaxation in the isotropic, cholesteric and blue phases have been carried out for the first time [P. Kędziora, K.W. Wojciechowski, J. Phys. Chem. B 113, 9123 (2009)].

During the period of 2009-2017 three research projects were conducted. Two of them concerned the influence of particle size polydispersity on elastic properties of the studied model systems. Auxetic properties were observed in a number of systems. It has been also shown that (at high pressure limit) the disorder causes an increase of the average Poisson's ratio to the extreme positive value which is possible for isotropic materials. The third project concerned computer modeling of auxetic foams. Among others, it has been shown that by compressing model foams of positive Poisson's ratios and removing the internal stresses one obtains auxetic foams.

Publications

Publications: 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010, 2009, 2008, 2007, 2006, 2005

2021

  1. M. Bilski, P.M. Piglowski, K.W. Wojciechowski
    Extreme Poisson's Ratios of Honeycomb, Re-Entrant, and Zig-Zag Crystals of Binary Hard Discs
    Symmetry-Basel 13, 1127, 2021
  2. J.N. Grima-Cornish, L. Vella-Zarb, K.W. Wojciechowski, J.N. Grima
    Shearing Deformations of beta-Cristobalite-Like Boron Arsenate
    Symmetry-Basel 13, 977, 2021
  3. J.W. Narojczyk, K.W. Wojciechowski, J. Smardzewski, A.R. Imre, J.N. Grima, M. Bilski
    Cancellation of Auxetic Properties in FCC Hard Sphere Crystals by Hybrid Layer-Channel Nanoinclusions Filled by Hard Spheres of Another Diameter
    Materials 14, 3008, 2021
  4. S. van Cleuvenbergen, G. Depotter, K. Clays, P. Kedziora
    Second-order NLO response in chiral ferroelectric liquid crystals: Molecular and bulk consideration
    Journal of Molecular Liquids 326, 115328, 2021
  5. J. Smardzewski, M. Maslej, K.W. Wojciechowski
    Compression and low velocity impact response of wood-based sandwich panels with auxetic lattice core
    European Journal of Wood and Wood Products 79, 797-810, 2021
  6. K.V. Tretiakov, K. Hyzorek
    Role of the phonon confinement effect and boundary scattering in reducing the thermal conductivity of argon nanowire
    Journal of Chemical Physics 154, 054702, 2021
  7. D. Morozow, M. Barlak, Z. Werner, M. Pisarek, P. Konarski, J. Zagorski, M. Rucki, L. Chalko, M. Lagodzinski, J. Narojczyk, Z. Krzysiak, J. Caban
    Wear Resistance Improvement of Cemented Tungsten Carbide Deep-Hole Drills after Ion Implantation
    Materials 14, 239, 2021
  8. M. Bilski, K.W. Wojciechowski, T. Stręk, P. Kędziora, J.N. Grima-Cornish, M.R. Dudek
    Extremely Non-Auxetic Behavior of a Typical Auxetic Microstructure Due to Its Material Properties
    Materials, 14, 7837, 2021

2020

  1. K.W. Wojciechowski, A. Alderson, J.N. Grima, F. Scarpa
    Auxetics and Other Systems with "Negative" Characteristics
    Physica Status Solidi B-Basic Solid State Physics 257, 2000496, 2020
  2. K.V. Tretiakov, K.W. Wojciechowski
    Auxetic, Partially Auxetic, and Nonauxetic Behaviour in 2D Crystals of Hard Cyclic Tetramers
    Physica Status Solidi-Rapid Research Letters 14, 2000198, 2020
  3. K.K. Dudek, R. Gatt, K.W. Wojciechowski, J.N. Grima
    Self-induced global rotation of chiral and other mechanical metamaterials
    International Journal of Solids And Structures 191, 212-219, 2020
  4. K.V. Tretiakov, K.W. Wojciechowski
    The Influence of the Soft Yukawa Potential and Hard Core Interactions on Auxeticity of the Face Centered Cubic Crystal of Hard-Core Repulsive Yukawa Particles
    Physica Status Solidi B-Basic Solid State Physics 257, 2000194, 2020
  5. K. Pelinski, J. Smardzewski, J. Narojczyk
    Stiffness of Synclastic Wood-Based Auxetic Sandwich Panels
    Physica Status Solidi B-Basic Solid State Physics 257, 1900749, 2020

2019

  1. K. Hyzorek, K. Ciesielczyk, K.V. Tretiakov
    Determination of thermal conductivity coefficient by Green-Kubo formula using the minimum image method
    Computational Methods in Science and Technology 25, 99-103 (2019)
  2. M.R. Dudek, K.K. Dudek, W. Wolak, K.W. Wojciechowski, J.N. Grima
    Magnetocaloric materials with ultra-small magnetic nanoparticles working at room temperature
    Scientific Reports 9, 17607, 2019
  3. J. Smardzewski, K.W. Wojciechowski
    Response of wood-based sandwich beams with three-dimensional lattice core
    Composite Structures 216, 340-349, 2019
  4. J.W. Narojczyk, K.W. Wojciechowski
    Poisson's Ratio of the f.c.c. Hard Sphere Crystals with Periodically Stacked (001)-Nanolayers of Hard Spheres of Another Diameter
    Materials 12, 700, 2019
  5. J.W. Narojczyk, K.W. Wojciechowski, K.V. Tretiakov, J. Smardzewski, F. Scarpa, P.M. Piglowski, M. Kowalik, A.R. Imre, M. Bilski
    Auxetic Properties of a f.c.c. Crystal of Hard Spheres with an Array of [001]-Nanochannels Filled by Hard Spheres of Another Diameter
    Physica Status Solidi B-Basic Solid State Physics 256, 1800611, 2019
  6. K.W. Wojciechowski, F. Scarpa, J.N. Grima, A. Alderson
    Auxetics and Other Systems of Anomalous Characteristics
    Physica Status Solidi B-Basic Solid State Physics 256, 1800736, 2019

2018

  1. K.V. Tretiakov, P.M. Piglowski, J.W. Narojczyk, M. Bilski, K.W. Wojciechowski
    High Partial Auxeticity Induced by Nanochannels in [111]-Direction in a Simple Model with Yukawa Interactions
    Materials 11, 2550, 2018
  2. K.V. Tretiakov, P.M. Piglowski, J.W. Narojczyk, K.W. Wojciechowski
    Selective enhancement of auxeticity through changing a diameter of nanochannels in Yukawa systems
    Smart Materials and Structures 27, 115021, 2018
  3. S. Huda, B. Weigelin, K. Wolf, K.V. Tretiakov, K. Polev, G. Wilk, M. Iwasa, F.S. Emami, J.W. Narojczyk, M. Banaszak, S. Sohl, D. Pilans, A. Vahid, M. Makurath, P. Friedl, G.G. Borisy, K. Kandere-Grzybowska, B.A. Grzybowski
    Levy-like movement patterns of metastatic cancer cells revealed in microfabricated systems and implicated in vivo
    Nature Communications 9, 4539, 2018
  4. J. Narojczyk, D. Morozow, J.W. Narojczyk, M. Rucki
    Ion implantation of the tool's rake face for machining of the Ti-6Al-4V alloy
    Journal of Manufacturing Processes 34, 274-280, 2018
  5. K.K. Dudek, K.W. Wojciechowski, M.R. Dudek, R. Gatt, L. Mizzi, J.N. Grima
    Potential of mechanical metamaterials to induce their own global rotational motion
    Smart Materials and Structures 27, 055007, 2018
  6. A.R. Imre, K.W. Wojciechowski, G. Gyorke, A. Groniewsky, J.W. Narojczyk
    Pressure-Volume Work for Metastable Liquid and Solid at Zero Pressure
    Entropy 20, 338, 2018
  7. J. Smardzewski, K.W. Wojciechowski, A. Pozniak
    Auxetic Lattice Truss Cores Fabricated of LayWood
    Bioresources 13, 8823-8838, 2018

2017

  1. T. Strek, H. Jopek, E. Idczak, K.W. Wojciechowski
    Computational Modelling of Structures with Non-Intuitive Behaviour
    Materials 10, 1386, 2017
  2. K.V. Tretiakov, M. Bilski, K.W. Wojciechowski
    Maximum Poisson's ratios in planar isotropic crystals of binary hard discs at high pressures
    Physica Status Solidi B 254, 1700543, 2017
  3. K.W. Wojciechowski, F. Scarpa, J.N. Grima, A. Alderson
    Auxetics and other systems of anomalous characteristics preface
    Physica Status Solidi B 254, 1770266, 2017
  4. P.M. Piglowski, J.W. Narojczyk, K.W. Wojciechowski, K.V. Tretiakov
    Auxeticity enhancement due to size polydispersity in fcc crystals of hard-core repulsive Yukawa particles
    Soft Matter 13, 7916-7921, 2017
  5. P.M. Piglowski, J.W. Narojczyk, A.A. Pozniak, K.W. Wojciechowski, K.V. Tretiakov
    Auxeticity of Yukawa Systems with Nanolayers in the (111) Crystallographic Plane
    Materials 11, 1338, 2017
  6. K.K. Dudek, W. Wolak, M.R. Dudek, R. Caruana-Gauci, R. Gatt, K.W. Wojciechowski, J.N. Grima
    Programmable magnetic domain evolution in magnetic auxetic systems
    Physica Status Solidi-Rapid Research Letters 11, 1700122, 2017
  7. S. van Cleuvenbergen, P. Kedziora, J.L. Fillaut, T. Verbiest, K. Clays, H. Akdas-Kilig, F. Camerel
    Chiral side groups trigger second harmonic generation activity in 3D octupolar bipyrimidine-based organic liquid crystals
    Angewandte Chemie-International Edition 56, 9546-9550, 2017

2016

  1. K.W. Wojciechowski, F. Scarpa, J.N. Grima, A. Alderson
    Auxetics and other systems of "negative" characteristics Preface
    Physica Status Solidi B 253, 1241-1242, 2016
  2. M. Bilski, K.W. Wojciechowski
    Tailoring Poisson's ratio by introducing auxetic layers
    Physica Status Solidi B 253, 1318-1323, 2016
  3. J.W. Narojczyk, M. Kowalik, K.W. Wojciechowski
    Influence of nanochannels on Poisson's ratio of degenerate crystal of hard dimers
    Physica Status Solidi B 253, 1324-1330, 2016
  4. P.M. Piglowski, K.W. Wojciechowski, K.V. Tretiakov
    Partial auxeticity induced by nanoslits in the Yukawa crystal
    Physica Status Solidi-Rapid Research Letters 10, 566-569, 2016
  5. A.A. Pozniak, K.W. Wojciechowski, J.N. Grima, L. Mizzi
    Planar auxeticity from elliptic inclusions
    Composites Part B 94, 379-388, 2016
  6. K. Hyzorek, K.V. Tretiakov
    Thermal conductivity of liquid argon in nanochannels from molecular dynamics simulations
    Journal of Chemical Physics 144, 194507, 2016
  7. F. Scarpa, A. Alderson, M. Ruzzene, K. Wojciechowski
    Auxetics in smart systems and structures 2015 Preface
    Smart Materials and Structures 25, 050301, 2016
  8. T. Strek, H. Jopek, K.W. Wojciechowski
    The influence of large deformations on mechanical properties of sinusoidal ligament structures
    Smart Materials and Structures 25, 054002, 2016
  9. K.V. Tretiakov, P.M. Piglowski, K. Hyzorek, K.W. Wojciechowski
    Enhanced auxeticity in Yukawa systems due to introduction of nanochannels in [001]-direction
    Smart Materials and Structures 25, 054007, 2016
  10. K.K. Dudek, D. Attard, R. Caruana-Gauci, K.W. Wojciechowski, J.N. Grima
    Unimode metamaterials exhibiting negative linear compressibility and negative thermal expansion
    Smart Materials and Structures 25, 025009, 2016
  11. E.G. Soboleva, A.L. Igisheva, K.W. Wojciechowski
    Elasticity of the Sm1-xYxS alloy based on ultrasonic measurements
    IOP Conference Series-Materials Science and Engineering 142, 012029, 2016
  12. B.T. Maruszewski, W. Muschik, A. Radowicz, K.W. Wojciechowski
    Special issue trends in continuum physics (TRECOP 2014) Preface
    Journal of Mechanics of Materials and Structures 11, 1-2, 2016
  13. K. Hyzorek, K.V. Tretiakov
    Limitations of Applicability of the Green-Kubo Approach for Calculating the Thermal Conductivity of a Confined Liquid in Computer Simulations
    Computational Methods in Science and Technology 22(4), 197-200, 2016
  14. T. Walczak, G. Sypniewska-Kaminska, B.T. Maruszewski, K.W. Wojciechowski
    The application of the method of fundamental solutions in modeling auxetic materials
    Journal of Mechanics of Materials and Structures 11, 79-90, 2016

2015

  1. L. Mizzi, D. Attard, R. Gatt, A.A. Pozniak, K.W. Wojciechowski, J.N. Grima
    Influence of translational disorder on the mechanical properties of hexachiral honeycomb systems
    Composites Part B 80, 84-91, 2015
  2. M.R. Dudek, K.W. Wojciechowski, J.N. Grima, R. Caruana-Gauci, K.K. Dudek
    Colossal magnetocaloric effect in magnetoauxetic systems
    Smart Materials and Structures, 24, 085027, 2015
  3. J.W. Narojczyk, P.M. Piglowski, K.W. Wojciechowski, K.V. Tretiakov
    Elastic properties of mono- and polydisperse two-dimensional crystals of hard-core repulsive Yukawa particles
    Phys. Status Solidi B 252, 1508-1513, 2015
  4. K.V. Tretiakov, K.W. Wojciechowski
    Quick and accurate estimation of the elastic constants using the minimum image method
    Computer Phys. Commun. 189, 77-83, 2015
  5. T.B. Dinh, V.C. Long, K.W. Wojciechowski
    Solitary waves in auxetic rods with quadratic nonlinearity: Exact analytical solutions and numerical simulations
    Phys. Status Solidi B 252, 1587-1594, 2015
  6. J.N. Grima, S. Winczewski, L. Mizzi, M.C. Grech, R. Cauchi, R. Gatt, D. Attard, K.W. Wojciechowski, J. Rybicki
    Tailoring Graphene to Achieve Negative Poisson’s Ratio Properties
    Advanced Materials 27, 1455-1459, 2015
  7. K.W. Wojciechowski, F. Scarpa, J.N. Grima, A. Alderson
    Auxetics and other systems of "negative" characteristics Preface
    Phys. Status Solidi B 252, 1421-1425, 2015
  8. H. Akdas-Kilig, M. Godfroy, J.L. Fillaut, B. Donnio, B. Heinrich, P. Kedziora, J.P. Malval, A. Spangenberg, S. van Cleuvenbergen, K. Clays, F. Camerel
    Mesogenic, luminescence, and nonlinear optical properties of new bipyrimidine-based multifunctional octupoles
    Journal Of Physical Chemistry C 119, 3697-3710, 2015

2014

  1. K.L. Alderson, A. Alderson, J.N. Grima, K.W. Wojciechowski
    Preface - Auxetic Materials and Related Systems
    Phys. Status Solidi B 251, No. 2, 263–266 (2014)
  2. P. Kędziora
    Dielectric relaxation modes in cholesteryl oleyl carbonate observed by non-linear dielectric spectroscopy
    Liq. Cryst., 41, 626-634 (2014)
  3. A.A. Pozniak, K.W. Wojciechowski
    Poisson’s ratio of rectangular anti-chiral structures with size dispersion of circular nodes
    Physica Status Solidi B 251, 367–374 (2014)
  4. I. Śliwa, A.V. Zakharov
    Transition Helmholtz free energy, entropy and heat capacity of free-standing smectic films in water: A   mean-field treatment
    Journal of Chemical Physics 141, 194706, 2014
  5. Z. Śniadecki, J.W. Narojczyk, B. Idzikowski
    Semi-Empirical Modelling of Glass Forming Ranges for Y-Co-Si System
    Acta Physica Polonica A 126, pp. 62-63, 2014
  6. K.V. Tretiakov, K.W. Wojciechowski
    Partially auxetic behavior in fcc crystals of hard-core repulsive Yukawa particles
    Physica Status Solidi B 251, 383-387 (2014)
  7. T. Walczak, G. Sypniewska-Kamińska, B.T. Maruszewski, K.W. Wojciechowski
    Mesh versus meshless method of elastic displacement determination in a common and an auxetic material
    Phys. Status Solidi B 251, No. 11, 2225–2232 (2014)
  8. A.V. Zakharov, I. Śliwa
    Surface tension and disjoining pressure of free-standing smectic films above the bulk smectic-A-isotropic transition temperature
    The Journal of Chemical Physics 140, 124705, 2014

2013

  1. J.N. Grima, R. Caruana-Gauci, M.R. Dudek, K.W. Wojciechowski, R. Gatt
    Smart metamaterials with tunable auxetic and other properties
    Smart Materials and Structures 22, 084016, 2013
  2. J.N. Grima, R. Caruana-Gauci, K.W. Wojciechowski, K.E. Evans
    Smart hexagonal truss systems exhibiting negative compressibility through constrained angle stretching
    Smart Materials and Structures 22, 084015, 2013
  3. D.M. Heyes, A.C. Brańka
    Lattice summations for spread out particles: applications to neutral and charged systems
    The Journal of Chemical Physics 138, 034504, 2013
  4. Sz. Maćkowiak, D.M. Heyes, D. Dini, A.C. Brańka
    Methods of Planes Normal Pressure for Slit Geometry in Molecular Dynamice Simulations
    Computational Methods in Sciences and Technology 19(3), 167, 2013
  5. A.A. Poźniak, J. Smardzewski, K.W. Wojciechowski
    Computer simulations of auxetic foams in two dimensions
    Smart Materials and Structures 22, 084009, 2013
  6. K.V. Tretiakov, K.W. Wojciechowski
    Elastic properties of fcc crystals of polydisperse soft spheres
    Physica Status Solidi B 250, 2020-2029, 2013
  7. K.V. Tretiakov, I. Szleifer, B.A. Grzybowski
    The Rate of Energy Dissipation Determines Probabilities of Non-equilibrium Assemblies
    Angewandte Chemie International Edition 52, 10304-10308, 2013
  8. K.V. Tretiakov, K.W. Wojciechowski
    Free Volume Approximation and Equation of State for the fcc Phase of Polydisperse Hard Spheres
    Computational Methods in Science and Technology 19(1), 59-64 (2013)
  9. K.W. Wojciechowski, J.N. Grima, K.L. Alderson, J. Rybicki
    Auxetic Materials and Related Systems Preface
    Physica Status Solidi B 250 (10), 1959-1962, 2013

2012

  1. A.C. Brańka, D.M. Heyes, Sz. Mackowiak, P. Pieprzyk, K.W. Wojciechowski
    Cubic materials in different auxetic regions: Linking microscopic to macroscopic formulations,
    Physica Status Solidi B 249(7), 1373-1378, 2012
  2. T. Bui Dinh, V. Cao Long, K. Dinh Xuan, K.W. Wojciechowski
    Computer simulation of solitary waves in a common or auxetic elastic rod with both quadratic and cubic nonlinearities
    Physica Status Solidi B 249(7), 1386-1392, 2012
  3. Ruben Gatt, J.N. Grima, J.W. Narojszyk, K.W. Wojciechowski
    Auxetic Materials and Related Systems
    Physica Status Solidi B 249(7), 1313-1314, 2012
  4. B. Idzikowski, S. Mielcarek, P. Misiuna, Z. Śniadecki, A.C. Brańka
    Mechanical properties of amorphous and partially crystalized Y50Cu24Al8 alloys
    Intermetallics 21, 75-79, 2012
  5. B.A. Grzybowski, B. Kowalczyk, I. Lagzi, D. Wang, K.V. Tretiakov,  D.A. Walker
    Inorganic salts direct the assembly of charged nanoparticles into composite nanoscopic spheres, plates, or needles
    Faraday Discussions 159, 201-209, 2012
  6. P. Kędziora
    Non-linear dielectric behaviour of 4,4‘-n-hexylcyanobiphenyl near the nematic-isotropic phase transition
    Liquid Crystals Vol. 39, No. 4, 425-432, 2012
  7. G. Rickayzen, A.C. Brańka, S. Pieprzyk, D.M. Heyes
    Single particle force distributions in simple fluids
    Journal of Chemical Physics 137, 094505, 2012
  8. B. T.Maruszewski, W. Muschik, J.N. Grima, K.W. Wojciechowski
    Special issue Trends in Continuum Physics (TRECOP 2010) PREFACE
    Source: Journal of Mechanics of Materials and Structures 7(3), 225-225 (2012)
  9. Z. Śniadecki, J.W. Narojczyk, B. Idzikowski
    Calculation of glass forming ranges in the ternary Y-Cu-Al system and its sub-binaries based on geometric and Miedema's models
    intermetallics 26, 72-77, 2012
  10. K. Tretiakov, K.W. Wojciechowski
    Elasticity of twodimensional crystals of polydisperse hard disks near close packing: surprising behavior of the Poisson’s ratio
    The Journal of Chemical Physics 136, 204506, 2012

2011

  1. K.L. Alderson, A. Alderson, K.W. Wojciechowski
    Auxetic Materials and Related Systems – Preface
    Physica Status Solidi B 248, 28-29 (2011)
  2. A.C. Brańka, D.M. Heyes
    Pair correlation function of soft-sphere fluids
    Journal of Chemical Physics 134, art. 064115 (2011)              
  3. A.C. Brańka, D.M. Heyes, G. Rickayzen
    Pair force distributions in simple fluids
    Journal of Chemical Physics 135, art. 164507 (2011)
  4. A.C. Brańka, D.M. Heyes, K.W. Wojciechowski
    Auxeticity of cubic materials under pressure
    Physica Status Solidi B 248, 96-104 (2011)
  5. P. Kołat, B.T. Maruszewski, K.V. Tretiakov, K.W. Wojciechowski
    Solitary waves in auxetic rods
    Physica Status Solidi B 248, 148-157 (2011)
  6. F. Scarpa, J.W. Narojczyk, K.W. Wojciechowski
    Unusual deformation mechanisms in carbon nanotube heterojunctions (5,5)-(10,10) under tensile loading
    Physica Status Solidi B 248, 82-87 (2011)
  7. F. Scarpa, J.W. Narojczyk, K.W. Wojciechowski, D.J. Inman
    Self-filtering oscillations in carbon nanotube hetero-junctions
    Nanotechnology 22, art. 465501 (2011)

2010

  1. M. Kowalik, K.V. Tretiakov, K.W. Wojciechowski
    On relative stability of selected hard tetramer solids.
    Computational Methods in Science and Technology 16, 141-146, 2010
  2. A.C. Brańka, S. Pieprzyk
    Configurational temperature and Monte Carlo simulations.
    Computational Methods in Science and Technology 16, 119-125, 2010
  3. A.A. Poźniak, H. Kamiński, P. Kędziora, B. Maruszewski, T. Stręk, K.W. Wojciechowski
    Anomalous Deformation of Constrained Auxetic Square.
    Reviews on Advanced Materials Science 23, 169-174, 2010
  4. J.W. Narojczyk, K.W. Wojciechowski
    Elastic properties of degenerate f.c.c. crystal of polydisperse soft dimers at zero temperature.
    Journal of Non-Crystalline Solids 356, 2026-2032, 2010
  5. P. Kolat, B.M. Maruszewski, K.W. Wojciechowski
    Solitary waves in auxetic plates.
    Journal of Non-Crystalline Solids 356, 2001-2009, 2010

2009

  1. K.V. Tretiakov, K.J.M. Bishop, B.A. Grzybowski
    The dependence between forces and dissipation rates mediating dynamics self-assembly.
    Soft Matter 5, 1279-1284, 2009
  2. A.C. Brańka, D.M. Heyes, K.W. Wojciechowski
    Auxeticity of cubic materials.
    Physica Status Solidi B, No. 9, 2063-2071, 2009
  3. M. Kowalik, K.W. Wojciechowski
    Elastic properties of orientationally disordered crystal of mono- and polydisperse hard dumbbells in three dimensions.
    Materials Science Poland 26(4), 977-981, 2008)
  4. J.W. Narojczyk, K.W. Wojciechowski
    Influence of size polydispersity on the elastic constants of fcc crystals of static soft spheres
    Materials Science Poland 26(4), 1001-1007, 2008
  5. D.M. Heyes, A.C. Brańka
    Density and pressure dependence of the equation of state and transport coefficients of soft-sphere fluids.
    Molecular Physics Vol. 107, No. 4-6, 309-319, 2009
  6. W. Jeżewski, K.W. Wojciechowski
    Nonlinear dielectric relaxation in the isotropic phase and mesophases of cholesteryl oleyl carbonate.
    Journal of Physical Chemistry B 113, 9123-9128, 2009
  7. K.V. Tretiakov, K.J.M. Bishop, B.A. Grzybowski
    Additivity of the excess energy dissipation rate in a dynamically self-assembled system.
    Journal of Physical Chemistry B 113, 7574-7578, 2009
  8. K.V. Tretiakov
    Negative Poisson’s ratio of two-dimensional hard cyclic tetramers.
    Journal of Non-Crystalline Solids 355, 1435-1438, 2009
  9. T. Stręk, P. Kędziora, B. Maruszewski, A.A. Poźniak, K.V. Tretiakov, K.W. Wojciechowski
    Finite element analysis of auetic obstacle deformation and fluid flow in a channel.
    Journal of Non-Crystalline Solids 355, 1387-1392, 2009
  10. D.M. Heyes, S.M. Clarke, A.C. Brańka
    Soft-sphere soft glasses
    J Chem Phys 131 (20): art. no. 204506 NOV 28 2009
  11. D.M. Heyes, A.C. Brańka
    Interactions between microgel particles
    Soft Matter 5, 2681, 2009

2008

  1. J.W. Narojczyk, K.W. Wojciechowski
    Elasticity of periodic and aperiodic structures of polydisperse dimers in two dimensions at zero temperature.
    phys. stat. sol. (b) 245, No. 11, 2463-2468, 2008
  2. R. Lakes, K.W. Wojciechowski
    Negative compressibility, negative Poisson’s ratio, and stability.
    physica status solidi (b) 245, No. 3, 545-551, 2008
  3. J.W. Narojczyk, K.W. Wojciechowski
    Elastic properties of the fcc crystals of soft spheres with size dispersion at zero temperature.
    physica status solidi (b) 245, No. 3, 606-613, 2008
  4. D.M. Heyes, A.C. Brańka
    Self-diffusion coefficients and shear viscosity of inverse power fluids: from hard- to soft-spheres.
    Physical Chemistry Chemical Physics 10, 4036-4044, 2008
  5. K.V. Tretiakov, K.W. Wojciechowski
    Elastic properties of soft sphere crystal from Monte Carlo simulations.
    Journal of Physical Chemistry B 112, 1699-1705, 2008
  6. A.R. Imre, A. Drozd-Rzoska, T. Kraska, S.J. Rzoska, K.W. Wojciechowski
    Spinodal strength of liquids, solids and glasses.
    Journal of Physics: Condensed Matter 20, 244104, 2008
  7. D.M. Heyes, A.C. Brańka
    Transport coefficients of soft repulsive particle fluids.
    Journal of Physics: Condensed Matter 20, 115102, 2008
  8. K.V. Tretiakov, K.W. Wojciechowski
    Poisson's ratio of binary and polydisperse soft disk crystals.
    Journal of Non-Crystalline Solids 354, 4484-4487, 2008
  9. T. Strek, B. Maruszewski, J.W. Narojczyk, K.W. Wojciechowski
    Finite element analysis of auxetic plate deformation.
    Journal of Non-Crystalline Solids 354, 4475-4480, 2008
  10. M.R. Dudek, K.W. Wojciechowski
    Magnetic films of negative Poisson’s ratio in rotating magnetic fields.
    Journal of Non-Crystalline Solids 354, 4304-4308, 2008
  11. M. Kowalik, K.W. Wojciechowski
    The free energy of hard dimer solids revisited.
    Journal of Non-Crystalline Solids 354, 4354-4358, 2008
  12. J.W. Narojczyk, A. Alderson, A.R. Imre, F. Scarpa, K.W. Wojciechowski
    Negative Poisson’s ratio behavior in the planar model of asymmetric trimers at zero temperature.
    Journal of Non-Crystalline Solids 354, 4242-4248, 2008
  13. A.C. Brańka, K.W. Wojciechowski
    Auxeticity of cubic materials: the role of repulsive core interaction.
    Journal of Non-Crystalline Solids 354, 4143-4145, 2008
  14. J.N. Grima, K.W. Wojciechowski
    Preface
    Physica Status Solidi (b), vol. 245 (11), 2369-2372, 2008
  15. B.T. Maruszewski, W. Muschik, K.W. Wojciechowski
    Preface 
    Journal of Mechanics of Materials and Structures 3(6), 1033-1035, 2008
  16. J. Rybicki, K.W. Wojciechowski, Nikolaos Gouskos
    Foreword
    Journal of Non-Crystalline Solids, vol. 354(35-39), vii-viii, 2008
  17. Ch.W. Smith, K.W. Wojciechowski
    Auxetics and related systems - Preface
    Physica Status Solidi (b), 245 (3): 486-488, 2008
  18. A.C. Brańka, D.M. Heyes
    Thermodynamic and mechanical stability of many-body systems interacting with coarse-grained bounded potentials
    Physica Status Solidi B, Nov. 2008; 245(11) 2415-2421

2007

  1. K.V. Tretiakov, K.W. Wojciechowski
    Poisson’s ratio of simple planar ‘isotropic’ solids in two dimensions.
    physica status solidi (b) 244, No. 3, 1038-1046, 2007
  2. J.W. Narojczyk, K.W. Wojciechowski
    Elastic properties of two-dimensional soft polydisperse trimers at zero temperature.
    physica status solidi (b) 244, No. 3, 943-954, 2007
  3. D.M. Heyes, A.C. Brańka
    Physical properties of soft repulsive particle fluids.
    Physical Chemistry Chemical Physics 9, 5570-5575, 2007
  4. K.V. Tretiakov, K.W. Wojciechowski
    Poisson’s ratio of a soft sphere system.
    Materials Science - Poland Vol. 25, No. 2, 542-544, 2007
  5. M.R. Dudek, B. Grabiec, K.W. Wojciechowski
    Molecular dynamics simulations of auxetic ferrogel
    Rev. Adv. Mater. Sci. 14, 167-173, 2007
  6. K.V. Tretiakov, K.W. Wojciechowski
    Elastic properties of soft disk crystals
    Rev. Adv. Mater. Sci. 14, 104-108, 2007

2006

  1. K.W. Wojciechowski, J.W. Narojczyk
    Infuence of disorder on the Poisson’s ratio of static solids in two dimensions.
    Reviews on Advanced Materials Sciences 12, 120-126, 2006
  2. A.C. Brańka, D.M. Heyes
    Thermodynamic properties of inverse power fluids.
    Physical Review E 47, 031202-1 do 031202-11, 2006
  3. J.W. Narojczyk, K.W. Wojciechowski
    Computer simulation of Poisson’s ratio of soft polydisperse discs at zero temperature.
    Materials Science – Poland, Vol. 24, No 4, 921-927, 2006
  4. D.M. Heyes, M. Cass, A.C. Brańka
    Percolation threshold of hard-sphere fluids in between the soft-core and hard-core limits.
    Molecular Physics Vol. 104, No. 20-21, 3137-3146, 2006
  5. D.M. Heyes, M. Cass, A.C. Brańka, H. Okumura
    First derivative of the hard-sphere radial distribution function at contact.
    Journal of Physics: Condensed Matter 18, 7553-7558, 2006
  6. C.R. Miranda, K.V. Tretiakov, S. Scandolo
    A computational study of elastic properties of disordered systems with voids.
    Journal of Non-Crystalline Solids 352, 4283-4286, 2006
  7. K.V. Tretiakov, K.W. Wojciechowski
    Elastic properties of the degenerate crystalline phase of two-dimensional hard dimers.
    Journal of Non-Crystalline Solids 352, 4221-4228, 2006
  8. J.W. Narojczyk, K.W. Wojciechowski
    Elastic properties of two-dimensional soft discs of various diameters at zero temperature.
    Journal of Non-Crystalline Solids 352, 4292-4298, 2006
  9. M. Kowalik, K.W. Wojciechowski
    Poisson’s ratio of orientationally disordered hard dumbbell crystal in three dimensions.
    Journal of Non-Crystalline Solids 352, 4269-4278, 2006

2005

  1. K.V. Tretiakov, K.W. Wojciechowski
    Monte Carlo simulation of two-dimensional hard body systems with extreme values of the Poisson’s ratio.
    physica status solidi (b) 242, No. 3, 2005, 730-741
  2. V.V. Novikov, K.W. Wojciechowski
    Extreme viscoelastic properties of composites of strongly inhomogeneous structures due to negative stiffness phases.
    physica status solidi b) 242, No. 3, 2005, 645-652
  3. M. Kowalik, K.W. Wojciechowski
    Poisson’s ratio of degenerate crystalline phases of three-dimensional hard dimers and hard cyclic trimers.
    physica status solidi (b) 242, No. 3, 2005, 626-631
  4. V.V. Novikov, K.W. Wojciechowski, O.A. Komkova, T. Thiel
    Anomalous relaxation in dielectrics. Equations with fractional derivatives.
    Materials Science – Poland, Vol. 23, No. 4, 977-984, 2005
  5. D.M. Heyes, A.C. Brańka
    Transport coefficients of soft sphere fluids.
    Physical Chemistry Chemical Physics 7, 2005, 1220-1227
  6. A.C. Brańka, D.M. Heyes
    The effects of particle softness on the dynamics of molecular and colloidal systems.
    Molecular Physics, Vol. 103, No. 17, 2359-2373, 2005
  7. K.V. Tretiakov, K.W. Wojciechowski
    Poisson’s ratio of the fcc hard sphere crystal at high densities.
    The Journal of Chemical Physics 123, 074509-1 do 074509-8, 2005
  8. K.W. Wojciechowski
    Poisson’s ratio of anisotropic systems
    Computational Methods in Science and Technology 11(1), 73-79, 2005
  9. K.W. Wojciechowski, A. Alderson, A.C. Brańka, K.L. Alderson (Guest Editors)
    Preface.
    Special issue of the Physica Status Solidi (b)242, March 2005