  We have observed a paramagnetic-to-ferromagnetic phase transition in short
period InGaMnAs/InGaAs superlattices. The thicknesses of magnetic InGaMnAs
layers in the structures studied was chosen to be 4 or 8 molecular layers (12
\AA or 24 \AA). The nonmagnetic InGaAs spacer layers are 12 \AA thick. The In
content of InGaMnAs and InGaAs layers was chosen in such a way that magnetic
layers were: deep potential wells, high potential barriers or shallow potential
wells. For superlattices with 8 monolayer thick InGaMnAs magnetic layers and 4
monolayer thick InGaAs nonmagnetic spacers the temperatures of
paramagnetic-to-ferromagnetic phase transition do not depend on the band
offsets between InGaMnAs and InGaAs adjusted by the In content.
