Ferromagnetism in Cr doped In₂O₃

In this work, we deposited 5%Ta-5%Cr-In₂O₃ film on LaAlO₃(001) substrate as an example to investigate the effect of electron doping, oxygen partial pressure and thickness on the ferromagnetism. The ferromagnetism is strongly dependent on oxygen partial pressure. Films deposited under low oxygen partial pressure leads to the enhancement of ferromagnetism. However, the electron doping through Ta dopant has a limit influence on the magnetism, suggesting that the film may not be carrier-mediated. Through the X-ray magnetic circular dichroism study, no magnetic moment can be found in Cr, In and O edge, suggesting that the ferromagnetism may be originated from defects. Magnetoresistance and anomalous Hall effect can be observed at low temperature in the film deposited under low oxygen partial pressure. Hence, these two properties may not be as an indication of intrinsic ferromagnetism.