Ferromagnetism and Anomalous Hall Effect in p-Zn_0.99Mn_0.01O:P

We report hole-induced ferromagnetism in diluted magnetic semiconductor $Zn_0.99Mn_0.01$ films grown on $SiO_2/Si$ substrates by reactive sputtering. The p-type conduction with hole concentration over $10¹⁸\;cm^-3$ is achieved by P doping followed by rapid thermal annealing at $800^\circC$ in a $N_2$ atmosphere. The p-type $Zn_0.99Mn_0.01O:P$ is carefully examined by x-ray diffraction and transmission electron microscopy. The magnetic measurements for $p-Zn_0.99Mn_0.01O:P$ clearly reveal ferromagnetic characteristics with a Curie temperature above room temperature, whereas those for $n-Zn_0.99Mn_0.01O:P$ show paramagnetic behavior. The anomalous Hall effect at room temperature is observed for the p-type film. This result strongly supports hole-induced room temperature ferromagnetism in $p-Zn_0.99Mn_0.01O:P$.