Fe-doped photocatalytic TiO2 film prepared by pulsed dc reactive magnetron sputtering

Fe-doped TiO2 films were prepared by means of the pulsed dc reactive magnetron cosputtering method using Ti and Fe mixed target. The deposition condition was optimized to produce uniform and transparent TiO2 films. The mixed target was more difficult to sputter out than the pure titanium target, whereas the threshold remained stable in spite of the variation of the fixed iron surface area, which controlled iron concentration in the Fe-doped TiO2 films. The sputtering rates of iron oxides were higher than that of titanium oxides. The surface morphologies of the Fe-doped films changed from uniform to rough when the iron concentration increased. The rutile phase took the place of the anatase phase after the iron concentration exceeded 15 at. %. Iron oxides phases appeared in the high iron concentration samples. The absorption edges of the Fe-doped TiO2 films shifted to visible region with the increasing concentration of iron oxides. The films with low iron concentrations showed better photocatalytic activity than the pure TiO2. On the contrary, the photocatalytic degradation rates of methyl orange on the highly iron doped TiO2 films decreased abruptly. 0 2003 American Vacuum Society.