Observability of hysteresis in first-order equilibrium and nonequilibrium phase transitions

The general conditions under which a system undergoing a first-order phase transition will exhibit hysteresis behavior, rather than simple jump behavior, are obtained. These are expressed in terms of the intrinsic time scales of the system and the time scale of variation of the control parameter. The size of the critical region is estimated. Estimates of the characteristic times are made for some equilibrium and nonequilibrium systems to show hysteresis behavior.