Propagation of Avalanches in Mn$_{12}$-acetate: Magnetic Deflagration
  Local time-resolved measurements of fast reversal of the magnetization of single crystals of Mn12-acetate indicate that the magnetization avalanche spreads as a narrow interface that propagates through the crystal at a constant velocity that is roughly two orders of magnitude smaller than the speed of sound. We argue that this phenomenon is closely analogous to the propagation of a flame front (deflagration) through a flammable chemical substance. 
Yoko Suzuki, M. P. Sarachik, E. M. Chudnovsky, S. McHugh, R.   Gonzalez-Rubio, Nurit Avraham, Y. Myasoedov, E. Zeldov, H. Sh...