Current–voltage characteristics of 30 period 390 Å GaAs/110 ÅAl0,3Ga0,7Assuperlattices are studied. Features revealed in multistable current branches of the hysteresis loops made it possible to estimate gradual changes in the size and shape of the domain boundary and reconstruct the final shape of the domain boundary. It was concluded that a considerable current bistability observed in the investigated superlattices is due to the domain boundary expansion. Switching between bistable current states in each hysteresis loop is detected. The switching time depends on the direction of the current jump. The switching time from a high- to low-current state is about10−7 s;the time of the reverse switching to the high-current state is about10−6 s.The observed switching is attributed to the shrinkage and expansion of the domain boundary size. ©1997 American Institute of Physics.