The influence of correlated impurities on the critical behaviour of the 3D
Ising model is studied using Monte Carlo simulations. Spins are confined into
the pores of simulated aerogels (diffusion limited cluster-cluster aggregation)
in order to study the effect of quenched disorder on the critical behaviour of
this magnetic system. Finite size scaling is used to estimate critical
couplings and exponents. Long-range correlated disorder does not affect
critical behavior. Asymptotic exponents differ from those of the pure 3D Ising
model (3DIS), but it is impossible, with our precision, to distinguish them
from the randomly diluted Ising model (RDIS).Comment: 10 pages, 10 figures. Submitted to Physical Review