The Effect of Nonmagnetic-Impurity Doping on the Curie Temperature and Magnetotransport Properties of Ga_(1-x)Mn_xAs

摘要

The effect of additional doping by nonmagnetic acceptor (Be) and donor (Te) impurities on the Curie temperature and anomalous Hall effect in Ga_(1-x)Mn_xAs is studied. As the Be concentration increases, the Curie temperature grows for Ga_(1-x)Mn_xAs with a comparatively low concentration of Mn (x - 0.03) and strongly decreases in the material with higher concentration of Mn x = 0.05. It is shown that the temperature dependence of the zero-magnetic-field resistivity (including the peak observed near the Curie temperature) can be adequately described by the magnetic- impurity scattering model. The additional doping with the donor (Te) impurity lowers the Curie temperature and enhances the anomalous Hall resistivity. As the Te concentration increases, the long-range ferromagnetic order in Ga_(1-x)Mn_xAs (x = 0.085) disappears and the paramagnet-spin glass transition is observed instead.