Ising model with periodic pinning of mobile defects.
Holtschneider, M., Selke, W.
Institut für Theoretische Physik, Technische Hochschule Aachen,
D-52056 Aachen, Germany
A two-dimensional Ising model with short-range interactions and
mobile defects describing the formation and thermal destruction of
defect stripes is studied. In particular, the effect of a local pinning
of the defects at the sites of straight equidistant lines is analysed
using Monte Carlo simulations and the tranfer matrix method. The pinning leads
to a long-range ordered magnetic phase at low temperatures. The dependence
of the phase transition temperature, at which the defect stripes
are destabilized, on the pinning strength is determined. The
transition seems to be of first order, with and without pinning.