AlN films doped with 3.2-8.2 at % Cu were deposited by helicon magnetron sputtering. The films exhibited ferromagnetism with a Curie temperature above 360 K. The observed magnetic anisotropy and exclusion of ferromagnetic contamination indicated that the ferromagnetism was the intrinsic property of Cu-doped AlN films. Room-temperature (RT) saturation magnetization (M s) tended to decrease with increasing Cu concentration and the maximum RT Ms obtained was about 8.5 emu/ cm3 (0.6 μBCu). Vacuum annealing increased the RT Ms values and meanwhile reduced ratio of N/ (Al+Cu), which suggested that Al interstitial and N vacancy might contribute to the observed ferromagnetic behavior.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)