Enhanced room-temperature ferromagnetism in Co and Er co-implanted MgO film.

• A filtered cathode vacuum arc (FCVA) system was used to grow MgO films on sapphire substrates. • The magnetic moment for the Er implanted MgO film is higher than that of Co implanted MgO. • The magnetization is enhanced by Co-Er co-doping compared with Co doped and Er doped MgO. • The origin of the magnetism can be described by the bound magnetic polaron (BMP) model. The present study reports a high ferromagnetism acquired by co-implanting Co and Er ions in MgO films prepared by filtered cathode vacuum arc on Al 2 O 3 substrates. The resulting MgO films were analyzed with respect to their structures, surface morphologies, and magnetic properties. Magnetic measurements show that substantial intrinsic ferromagnetism has been found for all the doped MgO. The ferromagnetism for the Er-doped MgO is larger than that of the Co-doped MgO and it is further strengthened by Er-Co co-doping. The X-ray photoelectron spectroscopy analysis substantiates that a large number of oxygen vacancies (V o) are generated after the doping of Er and Co ions. The origin of the magnetism can be described by the V o mediated bound magnetic polaron (BMP) model. The increased number of BMP with higher moments and the coupling interaction of Er and Co accounts for the strong ferromagnetism in the co-doped films. Our research provides a new idea for manufacturing high-quality diluted magnetic oxides by co-doping rare earth and transition metal ions in MgO samples. [ABSTRACT FROM AUTHOR]