Polymer-assisted deposition and room-temperature ferromagnetism of amorphous Mn-doped gallium oxide films

In this work, amorphous Mn-doped gallium oxide ( a -GMO) films are prepared by polymer-assisted deposition. The a -GMO films exhibit room-temperature ferromagnetism (RTFM) and their saturation magnetization ( M S ) and coercive field ( H C ) values are dependent on the Mn concentration. Interestingly, a lower Mn-doping concentration (3.1%) is sufficient to trigger the RTFM in the a -GMO films, in comparison with the previously-reported values in crystalline Mn-doped β-Ga 2 O 3 (11%) and γ-Ga 2 O 3 (7.0%). Furthermore, the a -GMO films exhibit higher M S values than those crystalline Mn-doped Ga 2 O 3 films at the medium doping levels between 10% and 20%. Further analysis shows that the enhancement of the ferromagnetism comes from the strong coupling between abundant oxygen vacancies (V O s) and Mn ions in the a -GMO films. Our results give insight to the RTFM of the a -GMO films and may be useful for the design, fabrication and application of spintronic materials based on gallium oxide.