1
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Rosenberg M, Kantorovich SS, Ivanov AO, Camp PJ. Structure and dynamics in suspensions of magnetic platelets. NANOSCALE 2024; 16:10250-10261. [PMID: 38713488 DOI: 10.1039/d4nr01120a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
In this research, we employ Brownian dynamics simulations, density functional theory, and mean-field theory to explore the profound influence of shape anisotropy of magnetic nanoplatelets on suspension magnetic response. Each platelet is modelled as an oblate cylinder with a longitudinal point dipole, with an emphasis on strong dipolar interactions conducive to self-assembly. We investigate static structural and magnetic properties, characterising the system through pair distribution function, static structure factor, and cluster-size distribution. The findings demonstrate that shape-specific interactions and clustering lead to significant changes in reorientational relaxation times. Under zero field, distinctive modes in the dynamic magnetic susceptibility identify individual particles and particle clusters. In the presence of an applied field, the characteristic relaxation time of clusters increases, while that of single particles decreases. This research provides insights into the intricate interplay between shape anisotropy, clustering, and magnetic response in platelet suspensions, offering valuable perspectives for recent experimental observations.
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Affiliation(s)
- Margaret Rosenberg
- Faculty of Physics, University of Vienna, Kolingasse 14-16, Vienna 1090, Austria.
- Research Platform MMM, University of Vienna, Oskar-Morgenstern-Platz 1, Vienna, Austria
| | - Sofia S Kantorovich
- Faculty of Physics, University of Vienna, Kolingasse 14-16, Vienna 1090, Austria.
- Research Platform MMM, University of Vienna, Oskar-Morgenstern-Platz 1, Vienna, Austria
| | - Alexey O Ivanov
- Ural Federal University, Lenin Avenue 51, Ekaterinburg, 620000, Russia
| | - Philip J Camp
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland, UK
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2
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Déjardin PM. Kinetic Yvon-Born-Green theory of the linear dielectric constant and complex permittivity of isotropic polar fluids. Phys Rev E 2022; 105:024109. [PMID: 35291169 DOI: 10.1103/physreve.105.024109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
The theory of the linear static dielectric constant and linear complex permittivity of isotropic polar fluids is formulated starting from the coupled Langevin equations describing the rototranslational dynamics of long-range interacting molecules with thermal agitation and subjected to external forces and torques. To this aim, adequate reduced densities are introduced and equations governing their dynamics derived. In the equilibrium zero frequency limit, integral expressions for the Kirkwood correlation factor g_{K} are given, transparently showing that the popular method consisting in comparing g_{K} with 1 in order to deduce pair dipolar ordering has no serious theoretical grounding. In the dynamical situation, the complex permittivity spectrum of a simple liquid is shown to exhibit an infinite discrete set of relaxation times, some of which may have thermally activated behavior. The theory is also shown to contain all previous results derived in the area provided molecular inertial effects are ignored, so restricting the range of validity of the theory to frequencies much below the far-infrared region. Finally, the theory can be adapted without much effort to relaxation of interacting magnetic nanoparticles for which macroscopic magnetic anisotropy arising from the assembly of nanoparticles is neglected.
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Affiliation(s)
- Pierre-Michel Déjardin
- Laboratoire de Modélisation Pluridisciplinaire et Applications, Université de Perpignan Via Domitia, 52 avenue Paul Alduy, F-66860 Perpignan, France
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3
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Ivanov AO, Camp PJ. Effects of interactions on magnetization relaxation dynamics in ferrofluids. Phys Rev E 2020; 102:032610. [PMID: 33075873 DOI: 10.1103/physreve.102.032610] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/01/2020] [Indexed: 11/07/2022]
Abstract
The dynamics of magnetization relaxation in ferrofluids are studied with statistical-mechanical theory and Brownian dynamics simulations. The particle dipole moments are initially perfectly aligned, and the magnetization is equal to its saturation value. The magnetization is then allowed to decay under zero-field conditions toward its equilibrium value of zero. The time dependence is predicted by solving the Fokker-Planck equation for the one-particle orientational distribution function. Interactions between particles are included by introducing an effective magnetic field acting on a given particle and arising from all of the other particles. Two different approximations are proposed and tested against simulations: a first-order modified mean-field theory and a modified Weiss model. The theory predicts that the short-time decay is characterized by the Brownian rotation time τ_{B}, independent of the interaction strength. At times much longer than τ_{B}, the asymptotic decay time is predicted to grow with increasing interaction strength. These predictions are borne out by the simulations. The modified Weiss model gives the best agreement with simulation, and its range of validity is limited to moderate, but realistic, values of the dipolar coupling constant.
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Affiliation(s)
- Alexey O Ivanov
- Department of Theoretical and Mathematical Physics, Ural Mathematical Center, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Philip J Camp
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland and Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
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4
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Mohapatra DK, Laskar JM, Philip J. Temporal evolution of equilibrium and non-equilibrium magnetic field driven microstructures in a magnetic fluid. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.112737] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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5
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Araujo WWR, Araujo JFDF, Oliveira CLP, Brito GES, Figueiredo Neto AM. Magnetic, structural and cation distribution studies on [Formula: see text] (x = 0.00, 0.02, 0.04, 0.06 and 0.1) nanoparticles. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2019; 42:153. [PMID: 31802279 DOI: 10.1140/epje/i2019-11917-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
We synthesized and characterized the colloidal suspensions of [Formula: see text] nanoparticles with x = 0.00, 0.02, 0.04, 0.06 and 0.1. The effect of the Fe3+ ion replacement by Nd3+ on the crystal structure is in-depth studied. The samples were characterized by the following techniques: X-ray diffraction (XRD), UV-Vis spectrophotometry, transmission electronic microscopy (TEM), small-angle X-ray scattering (SAXS), magnetization as a function of applied magnetic field (M-H loops) and magnetization as a function of temperature in zero-field-cooled and field-cooled regimes (ZFC-FC). From XRD cation distribution, structural parameters were extracted. The increasing in the bandgap is interpreted as a result of the higher interatomic separation with the doping. TEM micrographs reveal a polydisperse size and shape distribution of particles. The results for the volume-weighted average diameter measured by SAXS are consistent with those determined by XRD. From the M-H loops we found that the superparamagnetic (SPM) regime contributes with 95-97% for all samples, while only 3-5% contribution comes from the paramagnetic (PM) regime. The saturation magnetization increases in a steady manner upon increasing the Nd3+ ion molar ratio from 0.00 up to 0.06, reaching the maximum value of 105.8±0.4 Am2/kg at x = 0.06. It is worth to mention that the result for the saturation magnetization value are higher than that of the bulk material.
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Affiliation(s)
- W W R Araujo
- Institute of Physics, University of São Paulo, Rua do Matão 1371, 05508-090, São Paulo, SP, Brazil.
| | - J F D F Araujo
- Department of Physics, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - C L P Oliveira
- Institute of Physics, University of São Paulo, Rua do Matão 1371, 05508-090, São Paulo, SP, Brazil
| | - G E S Brito
- Institute of Physics, University of São Paulo, Rua do Matão 1371, 05508-090, São Paulo, SP, Brazil
| | - A M Figueiredo Neto
- Institute of Physics, University of São Paulo, Rua do Matão 1371, 05508-090, São Paulo, SP, Brazil
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6
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Robinson DR, Wilson M. Field-induced self-assembly: does size matter? Mol Phys 2018. [DOI: 10.1080/00268976.2018.1481233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- David R. Robinson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
| | - Mark Wilson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
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7
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Minina ES, Pyanzina ES, Novak EV, Kantorovich SS. Compressibility of ferrofluids: Towards a better understanding of structural properties. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2018; 41:67. [PMID: 29845486 DOI: 10.1140/epje/i2018-11678-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/14/2018] [Indexed: 06/08/2023]
Abstract
This paper addresses a computational method aimed at obtaining the isothermal compressibility of ferrofluids by means of molecular dynamics (MD) simulations. We model ferrofluids as a system of dipolar soft spheres and carry out MD simulations in the NPT ensemble. The obtained isothermal compressibility computed via volume fluctuations provides us with a strong evidence that dipolar interactions lead to a higher compressibility of dipolar soft sphere systems: the stronger the dipolar interactions, the bigger is the deviation of the compressibility from the one of a system with no dipoles. Furthermore, we use the isothermal compressibility to calculate the structure factor of ferrofluids at low values of wave vectors, i.e. in the range where it is difficult to predict its behaviour because of a problem with accounting for long-range particle correlations that give the main contribution to the structure factor in this range. Our approach based on the interpolation of the structure factor and the computed isothermal compressibility allows us to obtain the smooth structure factor in the range of low wave vectors and the reliable fractal dimension of the clusters formed in the system.
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Affiliation(s)
- Elena S Minina
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna, Austria.
- Ural Federal University, Lenin av. 51, Ekaterinburg, Russia.
| | | | | | - Sofia S Kantorovich
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna, Austria
- Ural Federal University, Lenin av. 51, Ekaterinburg, Russia
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Solovyova AY, Elfimova EA, Ivanov AO, Camp PJ. Modified mean-field theory of the magnetic properties of concentrated, high-susceptibility, polydisperse ferrofluids. Phys Rev E 2017; 96:052609. [PMID: 29347762 DOI: 10.1103/physreve.96.052609] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Indexed: 06/07/2023]
Abstract
The effects of particle-size polydispersity on the magnetostatic properties of concentrated ferrofluids are studied using theory and computer simulation. The second-order modified mean-field (MMF2) theory of Ivanov and Kuznetsova [Phys. Rev. E 64, 041405 (2001)1063-651X10.1103/PhysRevE.64.041405] has been extended by calculating additional terms of higher order in the dipolar coupling constant in the expansions of the initial magnetic susceptibility and the magnetization curve. The theoretical predictions have been tested rigorously against results from Monte Carlo simulations of model monodisperse, bidisperse, and highly polydisperse ferrofluids. Comparisons have been made between systems with the same Langevin susceptibility and the same saturation magnetization. In all cases, the new theoretical magnetization curve shows better agreement with simulation data than does the MMF2 theory. As for the initial susceptibility, MMF2 theory is most accurate for the monodisperse model, while the new theory works best for polydisperse systems with a significant proportion of large particles. These results are important for the analysis and characterization of recently synthesized polydisperse ferrofluids with record-breaking values of the initial magnetic susceptibility.
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Affiliation(s)
- Anna Yu Solovyova
- Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Ekaterina A Elfimova
- Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Alexey O Ivanov
- Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Philip J Camp
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland and Department of Theoretical and Mathematical Physics, Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
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9
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Solovyova AY, Goldina OA, Ivanov AO, Lebedev AV, Elfimova EA. The initial magnetic susceptibility of polydisperse ferrofluids: A comparison between experiment and theory over a wide range of concentration. J Chem Phys 2016; 145:084909. [DOI: 10.1063/1.4961405] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Anna Y. Solovyova
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Olga A. Goldina
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Alexey O. Ivanov
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Aleksandr V. Lebedev
- Institute of Continuous Media Mechanics, UB RAS, 1 Korolyov st., Perm 614013, Russia
| | - Ekaterina A. Elfimova
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
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10
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Sindt JO, Camp PJ. Simulations of dipolar fluids using effective many-body isotropic interactions. J Chem Phys 2015; 143:024501. [DOI: 10.1063/1.4923300] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Julien O. Sindt
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland
| | - Philip J. Camp
- School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, Scotland
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11
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Sreekumari A, Ilg P. Anisotropy of magnetoviscous effect in structure-forming ferrofluids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:012306. [PMID: 26274161 DOI: 10.1103/physreve.92.012306] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Indexed: 06/04/2023]
Abstract
The magnetoviscous effect, change in viscosity with change in magnetic field strength, and the anisotropy of the magnetoviscous effect, change in viscosity with orientation of magnetic field, have been a focus of interest for four decades. A satisfactory understanding of the microscopic origin of anisotropy of the magnetoviscous effect in magnetic fluids is still a matter of debate and a field of intense research. Here, we present an extensive simulation study to understand the relation between the anisotropy of the magnetoviscous effect and the underlying change in microstructures of ferrofluids. Our results indicate that field-induced chainlike structures respond very differently depending on their orientation relative to the direction of an externally applied shear flow, which leads to a pronounced anisotropy of viscosity. In this work, we focus on three exemplary values of dipolar interaction strengths which correspond to weak, intermediate, and strong interactions between dipolar colloidal particles. We compare our simulation results with an experimental study on cobalt-based ferrofluids as well as with an existing theoretical model called the chain model. A nonmonotonic behavior in the anisotropy of the magnetoviscous effect is observed with increasing dipolar interaction strength and is explained in terms of microstructure formation.
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Affiliation(s)
- Aparna Sreekumari
- Polymer Physics, Department of Materials, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
| | - Patrick Ilg
- Polymer Physics, Department of Materials, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
- Department of Mathematics and Statistics, University of Reading, Reading RG6 6AX, UK
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12
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Novak E, Minina E, Pyanzina E, Kantorovich S, Ivanov A. Structure factor of model bidisperse ferrofluids with relatively weak interparticle interactions. J Chem Phys 2014; 139:224905. [PMID: 24329091 DOI: 10.1063/1.4834635] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In the present manuscript we develop a theoretical approach to describe the pair correlation function of bidisperse magnetic dipolar hard- and soft-spheres. We choose bidisperse system as the first step to allow for polydispersity when studying thermodynamics of magnetic fluids. Using diagram technique we calculate the virial expansion of the pair correlation function up to the first order in density and fourth order in the dipolar strength. Even though, the radial distribution functions are extremely sensitive to the steric potential, we show that the behaviour of the isotropic centre-centre structure factor is almost indifferent to the type of the short-range repulsion. We extensively compare our theoretical results to the data of molecular dynamics simulations, which helps us to understand the range of validity of the virial expansion both on density and magnetic dipolar strength. We also investigate the influence of the granulometric composition on the height, width, and position of the structure factor first peak in order to clarify whether it is possible to extract structural information from experimentally measured small angle neutron scattering intensities.
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Affiliation(s)
- Ekaterina Novak
- Institute of Mathematics, Department of Mathematical Physics, Ural Federal University, Lenin av. 51, 620000 Ekaterinburg, Russia
| | - Elena Minina
- Institute for Computational Physics, Universiät Stuttgart, Allmandring 3, 70569 Stuttgart, Germany
| | - Elena Pyanzina
- Institute of Mathematics, Department of Mathematical Physics, Ural Federal University, Lenin av. 51, 620000 Ekaterinburg, Russia
| | - Sofia Kantorovich
- Institute of Mathematics, Department of Mathematical Physics, Ural Federal University, Lenin av. 51, 620000 Ekaterinburg, Russia
| | - Alexey Ivanov
- Institute of Mathematics, Department of Mathematical Physics, Ural Federal University, Lenin av. 51, 620000 Ekaterinburg, Russia
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Weeber R, Klinkigt M, Kantorovich S, Holm C. Microstructure and magnetic properties of magnetic fluids consisting of shifted dipole particles under the influence of an external magnetic field. J Chem Phys 2013; 139:214901. [DOI: 10.1063/1.4832239] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Large magneto-optical birefringence of colloidal suspensions of α-FeOOH goethite nanocrystallites. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.10.082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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15
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Virga EG. Exact second virial coefficient for dipolar hard spheres. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:465109. [PMID: 24158678 DOI: 10.1088/0953-8984/25/46/465109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The second virial coefficient B2 for a fluid of dipolar hard spheres has been given several approximate forms valid in the limits of weak and strong interactions. They have been formulated as asymptotic expressions in a dimensionless interaction parameter λ. In this paper, B2 is determined exactly for all values of λ in both the three-dimensional case, where spheres may access the whole space and their dipole moments may be oriented in all directions, and in the quasi-two-dimensional case, where spheres have their centres bound to glide on a plane, while their dipole moments are still freely orientable in space.
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Affiliation(s)
- Epifanio G Virga
- Dipartimento di Matematica, Università di Pavia, Via Ferrata 1, I-27100 Pavia, Italy
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16
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Elfimova EA, Ivanov AO, Camp PJ. Thermodynamics of ferrofluids in applied magnetic fields. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:042310. [PMID: 24229175 DOI: 10.1103/physreve.88.042310] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Indexed: 06/02/2023]
Abstract
The thermodynamic properties of ferrofluids in applied magnetic fields are examined using theory and computer simulation. The dipolar hard sphere model is used. The second and third virial coefficients (B(2) and B(3)) are evaluated as functions of the dipolar coupling constant λ, and the Langevin parameter α. The formula for B(3) for a system in an applied field is different from that in the zero-field case, and a derivation is presented. The formulas are compared to results from Mayer-sampling calculations, and the trends with increasing λ and α are examined. Very good agreement between theory and computation is demonstrated for the realistic values λ≤2. The analytical formulas for the virial coefficients are incorporated in to various forms of virial expansion, designed to minimize the effects of truncation. The theoretical results for the equation of state are compared against results from Monte Carlo simulations. In all cases, the so-called logarithmic free energy theory is seen to be superior. In this theory, the virial expansion of the Helmholtz free energy is re-summed in to a logarithmic function. Its success is due to the approximate representation of high-order terms in the virial expansion, while retaining the exact low-concentration behavior. The theory also yields the magnetization, and a comparison with simulation results and a competing modified mean-field theory shows excellent agreement. Finally, the putative field-dependent critical parameters for the condensation transition are obtained and compared against existing simulation results for the Stockmayer fluid. Dipolar hard spheres do not undergo the transition, but the presence of isotropic attractions, as in the Stockmayer fluid, gives rise to condensation even in zero field. A comparison of the relative changes in critical parameters with increasing field strength shows excellent agreement between theory and simulation, showing that the theoretical treatment of the dipolar interactions is robust.
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Affiliation(s)
- Ekaterina A Elfimova
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
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Takae K, Onuki A. Applying electric field to charged and polar particles between metallic plates: Extension of the Ewald method. J Chem Phys 2013; 139:124108. [DOI: 10.1063/1.4821085] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Annunziata MA, Menzel AM, Löwen H. Hardening transition in a one-dimensional model for ferrogels. J Chem Phys 2013; 138:204906. [DOI: 10.1063/1.4807003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Teixeira PIC. Effective isotropic potential for dipolar hard spheres. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:195102. [PMID: 23552475 DOI: 10.1088/0953-8984/25/19/195102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A new effective isotropic potential is proposed for the dipolar hard-sphere fluid, on the basis of recent results by others for its angle-averaged radial distribution function. The new effective potential is shown to exhibit oscillations even for moderately high densities and moderately strong dipole moments, which are absent from earlier effective isotropic potentials. The validity and significance of this result are briefly discussed.
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Affiliation(s)
- P I C Teixeira
- Instituto Superior de Engenharia de Lisboa, Lisbon, Portugal.
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