The temperature dependence of the electrical conductivity (O−) of pure and doped Fe2O3 using different elements ( Ti, Nb, Sn, Be, Cu, Ni, Mn, Mg and Zn ) in a concentration range of 0.01–2.0 atom % and over a temperature range of 25–500°C was investigated. The addition of Ti, Nb or Sn to pure Fe2O3 was observed to lead to an increase in the conductivity (O−) and to a decrease in the activation energy ( Ea ), whereas the addition of Be, Cu, Ni or Mn showed the reverse action. On using Mg or Zn as a doping element at a concentration of 0.01 atom %, the value of the conductivity ( O−) decreases and that of the activation energy ( Ea ) increases with respect to those of the pure Fe2O3. On the other hand, on using a higher concentration (>0.01 atom % ) the reverse behaviour was observed. Furthermore, the effect of γ -irradiation ( in different doses ) on both the conductivity and the activation energy of pure Fe2O3 was studied, and the damage produced was isothermally annealed and studied.The Seebeck voltages of the irradiated and unirradiated Fe2O3 samples have been measured. The formation of the Fe(II) ions as a major impurity in the Fe2O3 -lattice after the irradiation process was also proved |
