Transport properties of ferromagnetic GaMnAs interfaced with paramagnetic ZoMnSe in the form of bilayer structures

摘要

We have investigated the magnetotransport properties of a series of magnetic semiconductor bilayer structures consisting of 300-nm-thick Ga_(1-x)Mn_XAs and 150-nm-thick Zn_(1-y)Mn_ySe layers. The temperature scan of resistance and an Arrot plot obtained from Hall resistance data showed that the Curie temperature (T_C) of the GaMnAs/ZnMnSe bilayer is higher than that of the bare GaMnAs. Furthermore, magnetoresistance measurement reveals significant enhancement of the magnetic hardness of the GaMnAs system in bilayer form even though the magnetic easy axis of the GaMnAs was not altered by the neighboring ZnMnSe layer. This observation indicates that the magnetotransport properties of GaMnAs can be changed by an adjacent magnetic layer due to the interactions between the two magnetic layers.