  Coupling an antisymmetric tensor field to the electromagnetic field in a
dyonic Reissner-Nordstr\"om-AdS black hole background, we build a holographic
model for the paramagnetism/ferromagnetism phase transition. In the case of
zero magnetic field, the time reversal symmetry is broken spontaneously and
spontaneous magnetization happens in low temperature. The critical exponents
are in agreement with the ones from mean field theory. In the case of nonzero
magnetic field, the model realizes the hysteresis loop of single magnetic
domain and the magnetic susceptibility satisfies the Curie-Weiss law.
