Free energy of dipolar hard spheres: The virial expansion under the presence of an external magnetic field

2014 ◽  
Vol 415 ◽  
pp. 210-219 ◽  
Author(s):  
Ekaterina A. Elfimova ◽  
Tatyana E. Karavaeva ◽  
Alexey O. Ivanov
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
External Magnetic Field ◽  
Hard Spheres ◽  
Virial Expansion

Thermodynamics of Bidisperse Ferrofluids in Zero External Magnetic Field: Theory and Simulations

2015 ◽  
Vol 233-234 ◽  
pp. 331-334
Author(s):  
Anna Yu. Solovyova ◽  
Ekaterina A. Elfimova
Keyword(s):  
Magnetic Field ◽  
Field Theory ◽  
Free Energy ◽  
External Magnetic Field ◽  
Volume Concentration ◽  
Helmholtz Free Energy ◽  
Hard Spheres ◽  
Particle Volume ◽  
Simulation Data ◽  
Theoretical Predictions

The thermodynamic properties of a ferrofluid modeled by a bidisperse system of dipolar hard spheres in the absence of external magnetic field are investigated using theory and simulations. The theory is based on the virial expansion of the Helmholtz free energy in terms of particle volume concentration. Comparison between the theoretical predictions and simulation data shows a great agreement of the results.

Short-time self-diffusion, collective diffusion and effective viscosity of dilute hard sphere magnetic suspensions

2016 ◽  
Vol 791 ◽  
pp. 237-259
Author(s):  
Krzysztof A. Mizerski ◽  
Eligiusz Wajnryb
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Effective Viscosity ◽  
Hard Spheres ◽  
Magnetic Interactions ◽  
Point Dipole ◽  
Basic Principles ◽  
Self Diffusion ◽  
Viscosity Coefficients ◽  
Short Time

The virial corrections to short-time self- and collective diffusion coefficients as well as the effective viscosity are calculated for suspensions of hard spheres with the same radii and constant (blocked within the particle) magnetization modelled by a point dipole. Analytic, integral formulae derived from basic principles of statistical mechanics are provided for both cases – in the absence and in the presence of an external magnetic field. In the former case the diffusion and viscosity coefficients are evaluated numerically as a function of the strength of magnetic interactions between the particles and it is reported that the translational collective diffusion coefficient is significantly greater than all the other coefficients. In the presence of an external magnetic field the coefficients become anisotropic and are evaluated in the asymptotic regime of weak interparticle magnetic interactions.

Equilibrium configurations of Vlasov plasmas carrying a current component along an external magnetic field

1972 ◽  
Vol 7 (3) ◽  
pp. 445-459 ◽  
Author(s):  
J. R. Kan
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
External Magnetic Field ◽  
Constant Field ◽  
Current Component ◽  
Equilibrium Solutions ◽  
Plasma Parameters ◽  
Equilibrium Configurations ◽  
Field Aligned Current ◽  
A Current

A class of equilibrium configurations of Vlasov plasmas carrying a current component along an external magnetic field is presented. The present slab model contains the diamagnetic current jy, and the field-aligned current jz for arbitrary βc (= particle pressure/magnetic pressure of the applied constant field). For fixed βc and field-aligned current, our model admits a family of equilibrium solutions in which the diamagnetic currents range from zero to a maximum value. The amount of diamagnetic current flowing in a machine depends on the width of the machine, the field-aligned current and other plasma parameters. The Helmholtz free energy of the system is calculated under the constraints that the total number of particles and the field-aligned current are conserved. The least unstable equilibrium configuration in a machine is obtained by minimizing the free energy under the stated constraints among all equilibria whose plasma widths do not exceed the width of the machine.

LARGE DEVIATIONS AND THE RANDOM ENERGY MODEL

2001 ◽  
Vol 15 (01) ◽  
pp. 1-15 ◽  
Author(s):  
T. C. DORLAS ◽  
J. R. WEDAGEDERA
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
External Magnetic Field ◽  
Large Deviation ◽  
Error Correcting Codes ◽  
Energy Model ◽  
Random Energy Model ◽  
Recent Letter ◽  
Random Energy ◽  
Deviation Property

We present a simple proof of the formula for the free energy of the random energy model using a large deviation property which holds almost surely with respect to the randomness. This proof is extended to the case with external magnetic field leading to the solution of a model with higher-order ferromagnetic term. It is shown that this model is useful for Sourlas' application to error-correcting codes as was already pointed out in a recent letter by the authors.

scholarly journals Excitation of electrostatic ion-cyclotron-like modes by the electron density ripple in dusty magnetoplasmas

2009 ◽  
Vol 75 (4) ◽  
pp. 433-436
Author(s):  
P. K. SHUKLA
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
External Magnetic Field ◽  
Electron Density ◽  
Mathieu Equation ◽  
Ion Cyclotron ◽  
Unstable Solutions

AbstractIt is shown that electrostatic ion-cyclotron (EIC)-like modes can be excited by the pre-existing electron density ripple across the external magnetic field in a dusty magnetoplasma. For this purpose, we use the ion continuity and momentum equations, together with the Boltzmann-distributed electrons, and derive the standard Mathieu equation. The latter admits unstable solutions, demonstrating that the EIC-like modes in dusty magnetoplasmas can be driven due to the free energy in the electron density ripple.

scholarly journals TYPE II ANYON SUPERCONDUCTIVITY

1995 ◽  
Vol 10 (20) ◽  
pp. 1455-1462
Author(s):  
JEWAN KIM ◽  
JUNGDAE KIM ◽  
TAEJIN LEE
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
External Magnetic Field ◽  
Physical Properties ◽  
Interaction Energy ◽  
Effective Action ◽  
Low Energy ◽  
Type Ii ◽  
Single Vortex ◽  
Chern Simons

Assuming that the superconductivity which is described by the low energy effective action of the anyon system may be type II, we discuss its characteristics. We also study physical properties of the Chern-Simons vortices, which may be formed as the external magnetic field is applied to the system, such as their statistics, the free energy of single vortex and the interaction energy between two vortices.

NUCLEATION OF SUPERCONDUCTIVITY IN A THIN DISK WITH A RING-LIKE DEFECT

2013 ◽  
Vol 27 (04) ◽  
pp. 1350025 ◽  
Author(s):  
J. BARBA-ORTEGA ◽  
EDSON SARDELLA ◽  
J. ALBINO AGUIAR
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
External Magnetic Field ◽  
Vortex State ◽  
Thin Disk ◽  
Pinning Force ◽  
Magnetization Curves ◽  
Disk Plane ◽  
Circular Defect ◽  
Superconducting Sample

We report on the influence of a circular defect on the vortex configuration in a mesoscopic superconducting sample. Effects associated with the pinning force of the circular defect on the configuration and on the vortex entry fields are studied for a very thin disk. We calculate the magnetization loop, vorticity, free energy and superconducting electrons for the disk in presence of an external magnetic field applied perpendicular to the disk plane. The magnetization curves are hysteretic, with paramagnetic response in part of the downward branch, also, in this part we found a vortex–anti-vortex state.

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