Postannealing effect on properties of hydrogenated amorphous Si(Mn) magnetic semiconductors

Postannealing effect was studied on films of hydrogenated amorphous silicon with Mn addition grown by magnetron cosputtering. Structural, magnetic, and electrical properties were investigated. We did not detect any second phases or clusters after annealing. Annealing enhances saturation magnetization, electrical conductivity, and carrier concentration by about 250%, 350%, and two orders of magnitude, respectively. Anomalous Hall effect was observed at 100 K, indicating ferromagnetism mediated by charge carriers. Moreover, the hydrogen concentration was determined by elastic recoil detection methods. The results revealed that there is no hydrogen effusion during annealing. The reason of property enhancement by annealing arises from the thermal energy to promote hydrogen diffusion; hence, a more homogeneous distribution and lessens defect density. (C) 2010 American Institute of Physics. [doi:10.1063/1.3352928]