STRAIN-INDUCED HELIMAGNETISM, FINITE THICKNESS EFFECTS, AND INTERLAYER COUPLING IN MAGNETIC SEMICONDUCTOR MULTILAYERS

Neutron diffraction studies of antiferromagnetic semiconductor superlattices are reviewed. Mn-VI/II-VI multilayers (e.g. MnSe/ZnTe, MnSe/ZnSe) exhibit a variety of strain-induced effects in spin ordering and phase transition phenomena. In MnTe/CdTe systems, in which the thickness of the non-magnetic CdTe spacers can be very thin (approximately 6 angstrom) and comparable with the range of the Mn-Mn exchange interactions, the measurements clearly show the onset of interlayer coupling. Pronounced interlayer coupling has been observed in experiments on another system, EuTe/PbTe, with much thicker (30-40 angstrom) non-magnetic layers - arguably, this coupling is maintained by dipolar fields.