Ferromagnetism in Cu-Doped ZnO Films Prepared by Filtered Cathodic Vacuum Arc Technique

Conductive copper-doped ZnO (ZnO:Cu) films exhibited room temperature ferromagnetism were fabricated by the filtered cathodic vacuum arc technique. The electron concentration and conductivity of the samples can be increased from 1016 to 1020 cm-3 and 0.31 to 194 (ohm-cm)-1 respectively, using the substrate biasing technique. However, this technique degrades the magnetic ordering of the conductive ZnO:Cu films. The magnetization of the films is not proportional to the increment of carrier concentration, suggesting carrier induce exchange is not directly responsible for magnetic properties. The magnetism of these biased ZnO:Cu is correlated to the crystal orientation, crystal quality and density of Zni.