Magnetization-controlled spin transport in DyAs/GaAs layers

Electrical transport properties of DyAs epitaxial layers grown on GaAs have been investigated at various temperatures and at magnetic fields up to 12 T. The measured magnetoresistances show two distinct peaks at fields around 0.2 and 2.5 T which are believed to arise from the strong spin-disorder sc attering occurring at the phase transition boundaries induced by the extern al magnetic field. An empirical magnetic phase diagram is deduced from the temperature dependence of magnetoresistance, and the anisotropic transport properties are also presented for various magnetic field directions with re spect to the current flow. (C) 2000 American Institute of Physics. [S0021-8 979(00)71808-1].