Heat treatment of anodic oxide films on titanium and niobium

Heat treatment of the oxide films in air makes them more conducting. This effect depends on the time and temperature. Capacitance of titanium oxide films as well as niobium oxide films increases on annealing. The conductivity patterns before and after heating show similar trends and are of two types, the one associated with high conductance and lower rate of change of capacitance with increase in temperature and the other associated with low conductance and changes capacitance more rapidly with increase in temperature. (author)