Magnetic domain patterns as self-organizing critical systems

In practice, large specimens of ferromagnetic materials settle into one of a large number of metastable states, not necessarily into the energetically lowest state. We suggest that they tend to select marginally stable states, in a manner similar to the process recently proposed by Bak, Tang, and Wiesenfeld. We apply this idea to the formation of the so-called zig-zag walls that separate oppositely magnetized domains in a magnetic recording tape.