Abstract
The characterization of Zn/TiO(2)and Ni/TiO(2)composites has been investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The AC conductivity was measured in the frequency range 0.1 kHz to 3 MHz at temperatures from 25 to 100 degrees C. X-ray diffraction results revealed the presence of the anatase phase of TiO2, while presenting low peaks of rutile phase attributed to the Ni and Zn traces in the TiO2. A peak shift was appearing for Ni-doped TiO(2)due to the change in the ionic radius which reduced the average particle size from 19 to 15 nm. The electrical conductivity was constant at low frequencies and increased with increasing frequency and doping with Zn and Ni, confirming the semiconductor nature of the samples and indicating localized/reorientation conduction mechanism. Interestingly, the frequency-dependent activation energy was found to be affected by the type of dopants.