scholarly journals Dynamics of interacting magnetic nanoparticles: effective behavior from competition between Brownian and Néel relaxation

2020 ◽  
Vol 22 (39) ◽  
pp. 22244-22259
Author(s):  
Patrick Ilg ◽  
Martin Kröger
Keyword(s):  
Monte Carlo ◽  
Magnetic Nanoparticles ◽  
Monte Carlo Method ◽  
Computer Simulations ◽  
Brownian Dynamics ◽  
Magnetization Dynamics ◽  
Steric Interactions ◽  
Néel Relaxation ◽  
Effective Behavior

We identify the influence of dipolar and steric interactions on the Brownian and Néel contributions to the magnetization dynamics of magnetic nanoparticles from extensive computer simulations using a combined Brownian dynamics/Monte-Carlo method.

Fast Monte Carlo method for magnetic nanoparticles

2006 ◽  
Vol 73 (9) ◽  
Author(s):  
P. Vargas ◽  
D. Altbir ◽  
J. d'Albuquerque e Castro
Keyword(s):  
Monte Carlo ◽  
Magnetic Nanoparticles ◽  
Monte Carlo Method

scholarly journals Self-Adaptive Acceptance Rate-Driven Markov Chain Monte Carlo Method Applied to the Study of Magnetic Nanoparticles

Computation ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 124
Author(s):  
Juan Camilo Zapata ◽  
Johans Restrepo
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Magnetic Nanoparticles ◽  
Monte Carlo Method ◽  
Magnetic Moments ◽  
Acceptance Rate ◽  
Wide Range ◽  
Acceptance Rates ◽  
Self Adaptive

A standard canonical Markov Chain Monte Carlo method implemented with a single-macrospin movement Metropolis dynamics was conducted to study the hysteretic properties of an ensemble of independent and non-interacting magnetic nanoparticles with uniaxial magneto-crystalline anisotropy randomly distributed. In our model, the acceptance-rate algorithm allows accepting new updates at a constant rate by means of a self-adaptive mechanism of the amplitude of Néel rotation of magnetic moments. The influence of this proposal upon the magnetic properties of our system is explored by analyzing the behavior of the magnetization versus field isotherms for a wide range of acceptance rates. Our results allows reproduction of the occurrence of both blocked and superparamagnetic states for high and low acceptance-rate values respectively, from which a link with the measurement time is inferred. Finally, the interplay between acceptance rate with temperature in hysteresis curves and the time evolution of the saturation processes is also presented and discussed.

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

Structures and crystallization of vacuum-deposited amorphous Se and Sb films

1990 ◽  
Vol 48 (4) ◽  
pp. 140-141
Author(s):  
Makoto Shiojiri ◽  
Toshiyuki Isshiki ◽  
Tetsuya Fudaba ◽  
Yoshihiro Hirota
Keyword(s):  
Monte Carlo ◽  
Electron Microscope ◽  
Monte Carlo Method ◽  
Computer Program ◽  
Radial Distribution ◽  
Film Formation ◽  
Amorphous State ◽  
Two Dimensional ◽  
Amorphous Films ◽  
Binding Condition

In hexagonal Se crystal each atom is covalently bound to two others to form an endless spiral chain, and in Sb crystal each atom to three others to form an extended puckered sheet. Such chains and sheets may be regarded as one- and two- dimensional molecules, respectively. In this paper we investigate the structures in amorphous state of these elements and the crystallization.HRTEM and ED images of vacuum-deposited amorphous Se and Sb films were taken with a JEM-200CX electron microscope (Cs=1.2 mm). The structure models of amorphous films were constructed on a computer by Monte Carlo method. Generated atoms were subsequently deposited on a space of 2 nm×2 nm as they fulfiled the binding condition, to form a film 5 nm thick (Fig. 1a-1c). An improvement on a previous computer program has been made as to realize the actual film formation. Radial distribution fuction (RDF) curves, ED intensities and HRTEM images for the constructed structure models were calculated, and compared with the observed ones.

Monte Carlo as Brownian dynamics

1998 ◽  
Vol 94 (3) ◽  
pp. 447-454 ◽  
Author(s):  
D.M. HEYES ◽  
A.C. BRANKA
Keyword(s):  
Monte Carlo ◽  
Brownian Dynamics
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