Comparison of Monte Carlo Surface Exchange With Radiative Continuum Results in Large Particle Dispersions

E. Nisipeanu; P. D. Jones

doi:10.1115/1.1287727

Comparison of Monte Carlo Surface Exchange With Radiative Continuum Results in Large Particle Dispersions

Journal of Heat Transfer ◽

10.1115/1.1287727 ◽

2000 ◽

Vol 122 (3) ◽

pp. 503-508 ◽

Cited By ~ 5

Author(s):

E. Nisipeanu ◽

P. D. Jones

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Radiation Intensity ◽

Large Particle ◽

Continuous Representation ◽

Surface Exchange ◽

Discontinuous Surface ◽

Radiative Fluxes ◽

Low Volume ◽

Continuous Representations

A Monte Carlo technique follows radiation intensity rays through a dispersion of particles. Rays reflect from and are absorbed by the surfaces of the particles that they encounter. Transmitted radiative fluxes are compared with Monte Carlo simulations of a radiative continuum, using properties from both independent and correlated scattering theories. Whereas both discontinuous (surface) and continuous representations of the medium yield similar results for high porosities (low volume fractions), the continuous representation yields transmission overpredictions for porosities less than 0.9, using independent scattering properties, and for porosities less than 0.7, using correlated scattering properties. The overprediction is less severe for less reflective particle surfaces. [S0022-1481(00)01603-0]

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Memory and superposition in a superspin glass

Scientific Reports ◽

10.1038/s41598-021-87345-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

D. Peddis ◽

K. N. Trohidou ◽

M. Vasilakaki ◽

G. Margaris ◽

M. Bellusci ◽

...

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Spin Glasses ◽

Ac Susceptibility ◽

Exchange Interactions ◽

Zero Field ◽

Interparticle Interactions ◽

Surface Exchange ◽

Atomic Spin ◽

Superspin Glass

AbstractThe non-equilibrium dynamics of the superspin glass state of a dense assembly of ~ 2 nm MnFe2O4 nanoparticles was investigated by means of magnetization, ac susceptibility and Mössbauer spectroscopy measurements and compared to the results of Monte Carlo simulations for a mesoscopic model that includes particles morphology and interparticle interactions. The zero-field cooled (ZFC), thermoremanent (TRM), and isothermal remanent magnetization (IRM) were recorded after specific cooling protocols and compared to those of archetypal spin glasses and their dimensionality. The system is found to display glassy magnetic features. We illustrate in detail, by a number of experiments, the dynamical properties of the low-temperature superspin glass phase. We observe that these glassy features are quite similar to those of atomic spin glasses. Some differences are observed, and interestingly, the non-atomic nature of the superspin glass is also reflected by an observed superspin dimensionality crossover. Monte Carlo simulations—that explicitly take into account core and surface contributions to the magnetic properties of these ultrasmall nanoparticles in direct contact, as well as interparticle interactions—evidence effects of the interplay between (intraparticle) core/surface exchange coupling and (interparticle) dipolar and exchange interactions.

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Distribution of the laser radiation intensity in turbid media: Monte Carlo simulations, theoretical analysis, and results of optoacoustic measurements

Quantum Electronics ◽

10.1070/qe2002v032n10abeh002308 ◽

2002 ◽

Vol 32 (10) ◽

pp. 868-874 ◽

Cited By ~ 14

Author(s):

P S Grashin ◽

Aleksander A Karabutov ◽

A A Oraevsky ◽

Ivan M Pelivanov ◽

N B Podymova ◽

...

Keyword(s):

Monte Carlo ◽

Laser Radiation ◽

Theoretical Analysis ◽

Monte Carlo Simulations ◽

Radiation Intensity ◽

Turbid Media ◽

Laser Radiation Intensity

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Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164854 ◽

1996 ◽

Vol 54 ◽

pp. 478-479

Author(s):

Matthew T. Johnson ◽

Ian M. Anderson ◽

Jim Bentley ◽

C. Barry Carter

Keyword(s):

Monte Carlo ◽

Quantitative Analysis ◽

Monte Carlo Simulations ◽

Cross Section ◽

Spatial Resolution ◽

Low Voltage ◽

Magnesium Ferrite ◽

X Ray ◽

Interaction Volume ◽

Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

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