Evidence for carrier-induced ferromagnetic ordering in Zn1-xMnxO thin films:: Anomalous Hall effect

The intrinsic origin of the ferromagnetic ordering in Zn1-xMnxO thin films grown by pulsed-laser deposition was investigated. The ferromagnetic behaviors for a Zn1-xMnxO (x=0.26) film grown at 700 degrees C under oxygen pressures of 10(-1) Torr were observed at 4 and 300 K. The anomalous Hall effect (AHE) was found at temperatures of up to 210 K for the Zn0.74Mn0.26O thin film. The anomalous Hall coefficients (R-A) were determined to be approximately proportional to the square of resistivity in the low field region, indicating the side-jump process for the AHE. Our results provide direct experimental evidence that a carrier-mediated mechanism is responsible for the ferromagnetic ordering in Zn1-xMnxO thin films grown by pulsed-laser deposition. (c) 2007 American Institute of Physics.