A facile method to increase dielectric properties of rutile TiO2

Investigations on dielectric properties of N2-sintered TiO2 ceramic samples followed by chemically oxidized in H2O2 aqueous solution with different time spans were performed in the frequency range of 102-106 Hz. The results reveal that the dielectric properties strongly depend on the lengths of oxidizing time. An optimum oxidizing time of 12-16 h gives rise to superior dielectric properties with the permittivity of 12589 and the loss factor of 0.34 at 100 Hz. The time effect is attributed to the formation of an insulating layer at grain boundaries. Chemical oxidation proves to be a facile strategy to manipulate the insulating layer and opens a new way to modify the dielectric permittivity of versatile oxides.