Critical phenomena at perfect and non-perfect surfaces
Pleimling, M. and Selke, W.
Institut für Theoretische Physik, Technische Hochschule Aachen,
D-52056 Aachen, Germany
The effect of imperfections on surface critical properties is
studied for Ising models with nearest-neighbour ferromagnetic
couplings on simple cubic lattices. In particular, results of
Monte Carlo simulations for flat, perfect surfaces are compared
to those for flat surfaces with random, 'weak' or 'strong',
interactions between neighbouring spins in the surface layer, and for
surfaces with steps of monoatomic height. Surface critical exponents
at the ordinary transition, in particular $\beta_1 = 0.80 \pm 0.01$,
are found to be robust against these perturbations.