Ferromagnetic III–Mn–V semiconductor multilayers: Manipulation of magnetic properties by proximity effects and interface design (invited)

We have investigated the degree to which magnetic properties of ferromagnetic (FM) III–Mn–V semiconductors can be modified by the proximity of other magnetic layers. This study was carried out on multilayers comprised of FM GaMnAs and either MnTe or ZnMnSe overlayers, both latter systems involving antiferromagnetic interactions between the Mn ions. The overlayers were grown directly adjacent to GaMnAs, or were separated from it by nonmagnetic layers (GaAs). We have observed that the presence of either MnTe or ZnMnSe overlayers leads to dramatic modifications of the coercive field of GaMnAs. In the case of GaMnAs/GaAs/MnTe multilayers the coercive field of GaMnAs could be modified by varying the thickness of the GaAs spacer. Additionally, in samples with both types of overlayers an increase in the Curie temperature was observed, as compared to “bare” GaMnAs.