Effect of defects on room-temperature ferromagnetism of Cr-doped ZnO films

We have investigated the microstructure and the magnetic properties of Zn 1− x Cr x O thin films deposited on squartz glass substrates using radiofrequency magnetron sputtering. The structural investigations demonstrate that the ferromagnetism observed at room temperature is an intrinsic property of Cr–ZnO films, and does not originate from any secondary phase. The experimental results show that defects due to singly negatively charged Zn vacancies, together with Cr doping, plays an important role in the ferromagnetic origin of Zn 1− x Cr x O thin films.