  We study the magnetic energy of magnetic polymer composite materials as the
average distance between magnetic particles vanishes. We model the position of
these particles in the polymeric matrix as a stochastic lattice scaled by a
small parameter $\varepsilon$ and the magnets as classical $\pm 1$ spin
variables interacting via an Ising type energy. Under surface scaling of the
energy we prove, in terms of $\Gamma$-convergence that, up to subsequences, the
(continuum) $\Gamma$-limit of these energies is finite on the set of
Caccioppoli partitions representing the magnetic Weiss domains where it has a
local integral structure. Assuming stationarity of the stochastic lattice, we
can make use of ergodic theory to further show that the $\Gamma$-limit exists
and that the integrand is given by an asymptotic homogenization formula which
becomes deterministic if the lattice is ergodic.
