Dynamics of electrical charge carriers in Mg-doped TiO2 thin films under reducing conditions

Mg-doped TiO2 thin ceramic films prepared using e-beam deposition were characterized by energy-dispersive X-ray spectroscopy, X-ray diffraction (XRD), and impedance spectrometer. The influence of the concentration of Mg dopant and systematic investigation of the dynamics of electronic charge carriers’ transport in the thin films are provided. The dopants concentration affected structural properties and nonlinear behaviour of electrical conductivity of the thin films. XRD analysis revealed anatase structure of TiO2 thin films with the decrease of cristallinity by increasing the concentration of Mg dopant. Total conductivity and activation energy depend on Mg concentration and the ambient temperature. The highest total conductivities 6.17E-6 S/cm and 5.50E-4 S/cm were achieved using 1.2 mol % (873 K) and 2.5 mol % (1230 K) dopant concentrations respectively. The highest relaxation frequencies and shortest relaxation times of 4.92E-02 s at 833 K and 3.48E-05 s at 1230 K temperature are obtained for the same experimental points, whereas the longest relaxation times 3.18E-01 s at 833 K and 1.21E-04 s at 1230 K temperature were estimated for 8 mol % Mg-doped TiO2 films.