Figure 1From: Influence of transition metal doping on the structural, optical, and magnetic properties of TiO2 films deposited on Si substrates by a sol–gel processXPS survey spectra of TM-doped TiO 2 thin films. (a) Ni-doped TiO2. (b) Co-doped TiO2. (c) Fe-doped TiO2.Back to article page