FREQUENCY DEPENDENT ELECTRICAL PROPERTIES OF TIO2/COO CORE - SHELL THIN FILMS

The frequency dependent electrical properties, [dielectrics] of TiO 2 /CoO core - shell thin films have been studied within the ultraviolet, visible and infrared regions of the electromagnetic radiations. Orthorhombic nanocrystallites have been induced by thermal annealing for the films as confirmed by XRD analysis. The optical absorption and transmission of these thin films were studied in the wavelength range from 200 - 1200nm using Perkin - Elmer Lambda - 2 spectrometer. The electrical properties of the films were also studied using the four points probe. However, our interest in this paper is in the dielectric properties only. TiO 2 /CoO core - shell thin films are semiconducting films with high dielectric loss. The films are good materials for storage cells in dynamic random acce ss memory and can also be used as infrared detectors. At lower frequencies [or lower photon energy values] the dielectrics of the films are not strongly dependent on the annealing temperatures. At higher frequencies,[or higher photon energy values], the di electric loss of the film samples annealed at higher temperatures decreased faster than the dielectric loss of the film samples annealed at lower temperatures.