References of "Dorosz, Sven 50001713"
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See detailDissipation by a crystallization process
Dorosz, Sven UL; Voigtmann, Thomas; Schilling, Tanja UL

in Europhysics Letters (2016), 113(10004),

We discuss crystallization as a non-equilibrium process. In a system of hard spheres under compression at a constant rate, we quantify the amount of heat that is dissipated during the crystallization ... [more ▼]

We discuss crystallization as a non-equilibrium process. In a system of hard spheres under compression at a constant rate, we quantify the amount of heat that is dissipated during the crystallization process. We interpret the dissipation as arising from the resistance of the system against phase transformation. An intrinsic compression rate is identified that separates a quasistatic regime from one of rapidly driven crystallization. In the latter regime the system crystallizes more easily, because new relaxation channels are opened, at the cost of forming a higher fraction of non-equilibrium crystal structures. We rationalize the change in the crystallization mechanism by analogy with shear thinning, in terms of a kinetic competition between near-equilibrium relaxation and external driving. [less ▲]

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See detailThe early crystal nucleation process in hard spheres shows synchronised ordering and densification
Berryman, Josh UL; Anwar, Muhammad UL; Dorosz, Sven UL et al

in Journal of Chemical Physics (2016), 145

We investigate the early part of the crystal nucleation process in the hard sphere fluid using data produced by computer simulation. We find that hexagonal order manifests continuously in the ... [more ▼]

We investigate the early part of the crystal nucleation process in the hard sphere fluid using data produced by computer simulation. We find that hexagonal order manifests continuously in the overcompressed liquid, beginning approximately one diffusion time before the appearance of the first “solid-like” particle of the nucleating cluster, and that a collective influx of particles towards the nucleation site occurs simultaneously to the ordering process: the density increases leading to nucleation are generated by the same individual particle displacements as the increases in order. We rule out the presence of qualitative differences in the early nucleation process between medium and low overcompressions and also provide evidence against any separation of translational and orientational order on the relevant lengthscales. [less ▲]

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See detailStrong Effect ofWeak Charging in Suspensions of Anisotropic Colloids
Dorosz, Sven UL; Shegokar, Nikhilesh; Schilling, Tanja UL et al

in Soft Matter (2014)

Suspensions of hard colloidal particles frequently serve as model systems in studies on fundamental aspects of phase transitions. But often colloidal particles that are considered as ``hard'' are in fact ... [more ▼]

Suspensions of hard colloidal particles frequently serve as model systems in studies on fundamental aspects of phase transitions. But often colloidal particles that are considered as ``hard'' are in fact weakly charged. If the colloids are spherical, weak charging has a only a weak effect on the structural properties of the suspension, which can be easily corrected for. However, this does not hold for anisotropic particles. We introduce a model for the interaction potential between charged ellipsoids of revolution (spheroids) based on the Derjaguin approximation of Debye--Hückel Theory and present a computer simulation study on aspects of the system's structural properties and phase behaviour. In line with previous experimental observations, we find that even a weak surface charge has a strong impact on the correlation functions. A likewise strong impact is seen on the phase behaviour, in particular, we find stable cubatic order in suspensions of oblate ellipsoids. [less ▲]

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See detailInfuence of random pinning on the crystallization process in suspensions of hard spheres
Dorosz, Sven UL; Schilling, Tanja UL

in Journal of Crystallization Process and Technology (2014), 4(2),

We discuss crystal formation in supersaturated suspensions of monodisperse hard spheres with a concentration of hard spheres randomly pinned in space and time. The pinning procedure introduces an external ... [more ▼]

We discuss crystal formation in supersaturated suspensions of monodisperse hard spheres with a concentration of hard spheres randomly pinned in space and time. The pinning procedure introduces an external length scale and an external time scale that restrict the accessible number of con gurations and ultimately the number of pathways leading to crystallization. We observe a signi cant drop in the nucleation rate density at a characteristic pinning concentration that can be directly related to the structure of the critical nucleus and the dynamics of its formation in the unpinned system. [less ▲]

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See detailMixtures of anisotropic and spherical colloids: Phase behavior, confinement, percolation phenomena and kinetics
Schilling, Tanja UL; Dorosz, Sven UL; Radu, Marc UL et al

in European Physical Journal. Special Topics (2013)

Purely entropic systems such as suspensions of hard rods, platelets and spheres show rich phase behavior. Rods and platelets have successfully been used as models to predict the equilibrium properties of ... [more ▼]

Purely entropic systems such as suspensions of hard rods, platelets and spheres show rich phase behavior. Rods and platelets have successfully been used as models to predict the equilibrium properties of liquid crystals for several decades. Over the past years hard particle models have also been studied in the context of non-equilibrium statistical mechanics, in particular regarding the glass transition, jamming, sedimentation and crystallization. Recently suspensions of hard anisotropic particles also moved into the focus of materials scientists who work on conducting soft matter composites. An insulating polymer resin that is mixed with conductive filler particles becomes conductive when the filler percolates. In this context the mathematical topic of connectivity percolation finds an application in modern nano-technology. In this article, we briefly review recent work on the phase behavior, confinement effects, percolation transition and phase transition kinetics in hard particle models. In the first part, we discuss the effects that particle anisotropy and depletion have on the percolation transition. In the second part, we present results on the kinetics of the liquid-to-crystal transition in suspensions of spheres and of ellipsoids. [less ▲]

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See detailCrystallization in glassy suspensions of hard ellipsoids
Dorosz, Sven UL; Schilling, Tanja UL

in Journal of Chemical Physics (2013), 139(12),

We have carried out computer simulations of overcompressed suspensions of hard monodisperse ellipsoids and observed their crystallization dynamics. The system was compressed very rapidly in order to reach ... [more ▼]

We have carried out computer simulations of overcompressed suspensions of hard monodisperse ellipsoids and observed their crystallization dynamics. The system was compressed very rapidly in order to reach the regime of slow, glass-like dynamics. We find that, although particle dynamics become sub-diffusive and the intermediate scattering function clearly develops a shoulder, crystallization proceeds via the usual scenario: nucleation and growth for small supersaturations, spinodal decomposition for large supersaturations. In particular, we compared the mobility of the particles in the regions where crystallization set in with the mobility in the rest of the system. We did not find any signature in the dynamics of the melt that pointed towards the imminent crystallization events. [less ▲]

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See detailFluctuation Relations and Crystallization in Colloidal Suspensions
Dorosz, Sven UL

Poster (2013, September)

Hard Spheres undergo a fluid to solid phase transition if the packing fraction is above $0.5$. The nucleation process itself and developing structures in this transient process are still matter of current ... [more ▼]

Hard Spheres undergo a fluid to solid phase transition if the packing fraction is above $0.5$. The nucleation process itself and developing structures in this transient process are still matter of current research. \\ Here a new approach is proposed to correlate forming structure and dissipation directly. The system driven externally by a time varying pressure is compressed in a finite time. Thermodynamic work measured and directly correlated to structural information recorded during the process. Fluctuation theorems set the framework of this analysis that still hold at the first order phase transition that are initialized by a macroscopic fluctuation. [less ▲]

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See detailFluctuation Relations and Crystallization
Dorosz, Sven UL

Poster (2013, August)

Hard Spheres undergo a fluid to solid phase transition if the packing fraction is approx. $>0.5$. The nucleation process itself and structure formation in this transient process are still under ... [more ▼]

Hard Spheres undergo a fluid to solid phase transition if the packing fraction is approx. $>0.5$. The nucleation process itself and structure formation in this transient process are still under investigation. Here a new approach is proposed to correlate forming structure and dissipation directly. Fluctuation relations are the method of choice. Increasing the pressure with time results in thermodynamic work, linked by the first law of thermodynamics to dissipation.\\ Studying fluctuation relations of structural phase transition and even slow dynamics is important. A new kind of fluctuation enters the dynamics that is macroscopic instead of microscopic based on thermal fluctuations. [less ▲]

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See detailCrystallization Close to the Glass Transition: Dynamic heterogeneities do not precede crystallization
Dorosz, Sven UL

Presentation (2013, July)

We address the question whether a crystallization event can be predicted based on observations of the mobility distribution in a supersaturated melt. We have carried out computer simulations of ... [more ▼]

We address the question whether a crystallization event can be predicted based on observations of the mobility distribution in a supersaturated melt. We have carried out computer simulations of overcompressed suspensions of hard monodisperse ellipsoids and observed their crystallization dynamics. The system was compressed very rapidly in order to reach the regime of slow, glass-like dynamics. We nd that, although particle dynamics become sub-diffusive and the intermediate scattering function clearly develops a shoulder, crystallization proceeds via the usual scenario: nucleation and growth for small supersaturations, spinodal decomposition for large supersaturations. In particular, we compared the mobility of the particles in those regions where crystallization set in with the mobility in the rest of the system. We did not find any signature in the dynamics that pointed towards the imminent crystallization event. [less ▲]

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See detailFluctuation Relations of Phase Transitions - Externally Driven Crystallization
Dorosz, Sven UL

Presentation (2013, February 15)

I will discuss the crystallization process in suspensions of hard particles far from equilibrium. The suspensions of hard particles, iniitially prepared in an equilibrium fluid state, are subjected to a ... [more ▼]

I will discuss the crystallization process in suspensions of hard particles far from equilibrium. The suspensions of hard particles, iniitially prepared in an equilibrium fluid state, are subjected to a time dependent over-compression protocol. During this process formation of crystallites and dynamic arrest take place. \\ This solidification process will be investigated in the framework of non-equilibrium fluctuation relations. For a given system driven far from equilibrium these relations state symmetries of the distribution of dissipated heat or mechanical work and ultimately relate to equilibrium free energy differences. The distribution of mechanical work, also experimentally accessible, contains important information about the evolution of crystallites and disorder in the system. Therefore, studying the distribution of mechanical work will offer new insights to the dynamical properties of the crystallization process and relate structural changes to dissipated energy far from equilibrium. \\ This presentation is based on ongoing research in the Theoretical Softmatter group at the University of Luxembourg. [less ▲]

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See detailHeterogenous Nucleation in Hard Spheres Systems
Dorosz, Sven UL

Scientific Conference (2012, May)

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See detailNucleation in Hard Spheres Systems
Dorosz, Sven UL

Presentation (2012, February 07)

I will be discussing the nucleation process in a system composed of mono-disperse hard spheres initially in an over-compressed fluid state. Molecular dynamics simulations are presented for the homogeneous ... [more ▼]

I will be discussing the nucleation process in a system composed of mono-disperse hard spheres initially in an over-compressed fluid state. Molecular dynamics simulations are presented for the homogeneous system and the dynamics and structure of the forming nucleus including the corresponding nucleation rates are discussed. In comparison to the studied homogenous nucleation event we will extend this system and introduce a substrate to study its influence onto nucleation within the fluid. In this case the substrate is made up of the same type of spheres held fixed in space throughout the simulation process on a triangular lattice modeling a crystalline surface. In general heterogenous nucleation, due to surfaces, walls as well as confinement are of great importancein experiments of colloidal suspensionsbecause strong effects are observed. In our case the substrates influence is studied by varying the substrate lattice constant as well as the fluid density. We observe qualitatively different dynamical regimes that will be discussed in detail. [less ▲]

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See detailDescription of hard sphere crystals and crystal-fluid interfaces: a critical comparison between density functional approaches and a phase field crystal model
Oettel, Martin; Dorosz, Sven UL; Berghoff, M. et al

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2012), 86(021404), 1-5

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See detailOn the influence of a patterned substrate on crystallization in suspensions of hard spheres
Dorosz, Sven UL; Schilling, Tanja UL

in Journal of Chemical Physics (2012), 136(issue 4), 1-5

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See detailHeterogenous Nucleation in Hard Spheres Systems
Dorosz, Sven UL

Poster (2011, September)

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See detailNucleation in Hard Spheres Systems
Dorosz, Sven UL

Presentation (2011, August)

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See detailHeterogenous Nucleation in Hard Spheres Systems
Dorosz, Sven UL

Poster (2011, August)

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See detailEntropy production far from equilibrium in interacting many-body systems
Dorosz, Sven UL

Presentation (2011, March)

La distribution de changement d'entropie est l'ingrédient principal dans les théorèmes de fluctuations. A l'aide de techniques numériques exactes on discute les distributions d'entropie pour des modèles ... [more ▼]

La distribution de changement d'entropie est l'ingrédient principal dans les théorèmes de fluctuations. A l'aide de techniques numériques exactes on discute les distributions d'entropie pour des modèles de réaction-diffusion. Les différents modèles sont analysés dans leurs états stationnaires et lorsqu' on les force hors de leur état stationnaire par un paramètre qui varie en temps. On montre un lien direct entre les propriétés des règles microscopiques et la création d'entropie. [less ▲]

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See detailEntropy production in the nonequilibrium steady states of interacting many-body systems
Dorosz, Sven UL; Pleimling, Michel

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2011), 83(3),

Detailed reference viewed: 50 (0 UL)