Magnetization curves as probes of Monte Carlo simulation of nonequilibrium states

Abstract

The influence of parameter choice in the Monte Carlo simulation of zero-field-cooled-field-cooled magnetization curves of granular systems is analyzed. The main simulation techniques are summarized and compared, in terms of the determination of macroscopic quantities usually associated with nanoscopic details of the sample.

Monte Carlo simulation of magnetic properties of irregular Fe islands on Pb/Si(111) substrate based on the scanning tunneling microscopy image

“…The algorithm of polar angle restriction 19 is used. The maximum changed range of polar angle is chosen to ensure the ordering temperature of the system without interaction close to 140 K that may be analytically estimated using the equation T B Ϸ͗K S V͘ / 25k B ͑K S and k B are the shape anisotropy constant and Boltzmann constant, respectively͒.…”

Superparamagnetism and Monte Carlo Simulations

“…Other transition probability algorithms as Glauber dynamics could provide similar results for simulating ZFC/FC magnetization curves [20]. Glauber dynamics, originally applied to the 1D-Ising model, mainly differs from Metropolis in that minimizing the energy is not always accepted as change.…”

“…In our simulations we use the solid angle restriction scheme [20]: the new trial orientation μ trial is randomly generated inside a cone of angle around the current orientation μ . Fig.…”

Geometric aspects of the dipolar interaction in lattices of small particles

“…Monte Carlo simulations were carried out using Metropolis algorithm with local dynamics in which the new orientation of the magnetic moment was chosen within a solid angle around the previous moment direction, with aperture dθ = dφ = 0.1. This method was studied by Pereira Nunes et al 20 , applied to the simulation of ZFC-FC magnetization curves, which are also a collection of nonequilibrium states, and it is a reasonable approach for a qualitative analysis. Monte Carlo simulations of hysteresis curves have been used in a variety of magnetic systems with good qualitative agreement with experimental data, so we believe that, although not specifically created to describe nonequilibrium processes, the method provides a valuable tool for studying the dynamics of complex systems.…”