  Ferromagnetism above room temperature was observed in Cr-doped hydrogenated
amorphous silicon films deposited by rf magnetron-sputtering. Structure
analysis reveals that films are amorphous without any detectable precipitates
up to the solubility limit 16 atomic percentages of Cr. Experimental results
suggest that hydrogenation has a dramatic influence on magnetic properties,
electrical conductivity and carrier concentration in the thin films. Pronounced
anomalous Hall effect and magnetization curve both suggest the origin of the
ferromagnetism may arises from percolation of magnetic polarons.
