Hysteresis and nucleation in condensed matter
  The physical origin of hysteresis in condensed matter had not been previously identified. The current "science of hysteresis" is useful, but limited by phenomenological modeling. This article fills the void by revealing the exclusive cause of the hysteresis in structural, ferromagnetic and ferroelectric phase transitions, as well as upon magnetization in magnetic fields and polarization in electric fields. This exclusive cause is nucleation lags. The lags are inevitable due to the nucleation specifics, far from the classical "random fluctuation" model. A major assumption that spin orientation is determined by the orientation of its carrier explains why ferromagnetic transitions and magnetization in magnetic fields materialize by structural rearrangements at interfaces, as well as why magnetization by "rotation" is impossible. Formation of the structural and ferromagnetic hysteresis loops is considered in detail. 
Yuri Mnyukh
physics.gen-ph