https://doi.org/10.1007/s100510050480
Nucleation and hysteresis in Ising model: classical theory versus computer simulation*
Institute for
Theoretical Physics, University of Cologne, 50923 Cologne, Germany
Corresponding author: a stauffer@thp.uni-koeln.de
Received:
21
January
1998
Accepted:
17
March
1998
Published online: 15 October 1998
We have studied the nucleation in
the nearest neighbour ferromagnetic Ising model, in different (d) dimensions,
by extensive Monte-Carlo simulation using the heat-bath dynamics.
The nucleation time (τ) has been studied as a
function of the magnetic field (h) for various system sizes in different
dimensions (d=2,3,4). The logarithm of
the nucleation time is found to be proportional to the power
() of the magnetic
field (h) in d dimensions.
The size dependent crossover from coalescence to nucleation regime
is observed in all dimensions.
The distribution
of metastable lifetimes are studied in both regions.
The numerical results are compared and found to be consistent
with the classical theoretical
predictions. In two dimensions, we have also studied the dynamical response
to a sinusoidally oscillating magnetic field.
The reversal time is studied as a function of the inverse of the coercive
field. The applicability of the classical nucleation theory to study the
hysteresis and coercivity has been discussed.
PACS: 05.50.+q – Lattice theory and statistics; Ising problems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998