We present an analysis of the structure of Bloch walls in layered
magnetic materials in
the context of micromagnetics. We have obtained the $\Gamma$-limit of a
one-dimensional reduction of
the Landau-Lifshitz energy for a double layer in several asymptotic
regimes. As a result, the optimal energy,
the core length, and the optimal shape of the Bloch wall have been
determined. The effects of the interlayer spacing and the film
thickness are studied. A comparison between the structure of the Bloch
and N\'eel walls in multilayers is carried out. We illustrate all our
findings by numerically
minimizing the one-dimensional energy.