Mn-doped ZnO and (Mn, Cu)-doped ZnO thin films: Does the Cu doping indeed play a key role in tuning the ferromagnetism?

摘要

Zn_(0.9)Mn_(0.1)O and Zn_(0.85)Mn_(0.1)Cu_(0.05)O thin films were grown by the pulsed laser deposition technique on R-cut Al_2O_3 substrates under various conditions. Both Zn_(0.9)Mn_(0.1)O and Zn_(0.85)Mn_(0.05)Cu_(0.05)O films that were fabricated at 650℃ under an oxygen pressure of 0.1 Torr show ferromagnetism (FM) above room temperature. It appears that by applying appropriate conditions, doping Mn alone can induce FM in ZnO itself, while co-doping with Cu might enhance the magnetic moment for some extent in some specific cases, but not very crucially as theories have predicted. Growth conditions likely play more important roles to result in ferromagnetic samples.