Ferromagnetism and anomalous Hall effect in Mn-doped ZnO thin films grown by reactive sputtering

In this work, the growth of Mn-doped p-type ZnO thin film by reactive sputtering and their conduction type dependent magnetic properties are reported. Mn-doped ZnO thin films are deposited on SiO/sub 2//Si substrates by reactive magnetron sputtering at 500/spl deg/C and P is used as p-type dopant in Mn-doped ZnO via ZnO target mixed with 10wt% P/sub 2/O/sub 5/. Rapid thermal annealing above 500/spl deg/C is also done. A p-type conduction with the highest concentration of 6.7 /spl times/ 10/sup 18/ cm/sup -3/ in Zn/sub 0.99/Mn/sub 0.01/O:P is accomplished by annealing at 800/spl deg/C under N/sub 2/ ambient. The p-type Zn/sub 0.99/Mn/sub 0.01/O:P film exhibits room temperature ferromagnetism with saturation magnetization of 0.301 emu/cm/sup 3/ and coercive field of 60 Oe in contrast with paramagnetism in n-type Zn/sub 0.99/Mn/sub 0.01/O:P. In addition, an anomalous Hall effect is observed at room temperature in p-type films. This result manifests the intrinsic nature of ferromagnetism, hole-induced ferromagnetism, in p-type Zn/sub 0.99/Mn/sub 0.01/O:P, and represents the possible realization of diluted magnetic semiconductor spintronic devices operable at room temperature.