A magnetic domain device comprising a layer of a magnetic material for the formation of magnetic domains, for example bubbles, under the influence of a bias magnetic field and a propagation structure with magnetically operating elements for driving the magnetic domains by the sequential formation thereon of preferred positions for the domains. The current conductors used to propagate the domains, either meander conductors or rotary field "coils", are arranged on a layer of silicon, so that the heat developed in the current conductors can readily be carried off by the silicon which exhibits a good thermal conductivity.