The phase diagram of binary mixtures of particles interacting via a pair
potential of parallel dipoles is computed at zero temperature as a function of
composition and the ratio of their magnetic susceptibilities. Using lattice
sums, a rich variety of different stable crystalline structures is identified
including AmBn structures. [A(B) particles correspond to large (small)
dipolar moments.] Their elementary cells consist of triangular, square,
rectangular or rhombic lattices of the A particles with a basis comprising
various structures of A and B particles. For small (dipolar) asymmetry
there are intermediate AB2 and A2B crystals besides the pure A and B
triangular crystals. These structures are detectable in experiments on granular
and colloidal matter.Comment: 6 pages - 2 figs - phase diagram update