Studies on Physical and Electrical Characterization of Al2O3-ZnO Composite Material and its Thick Films

Al2O3 - ZnO composite material was obtained by adding the Aluminium chloride (AlCl3 6H2O) (Hexahydrate) powder of different weight percent (0.5, 1 3, 5 and 7 wt %) and Analar Reagent grade (99.9 % pure) ZnO powder by mixing mechnochemically in acetone medium. The prepared materials were sintered at 1000oC for 12h in air ambience and ball milled to ensure sufficiently fine particle size. The structural properties of the powder materials were investigated by X-ray diffraction analysis. The observed powder materials show the polycrystalline nature and the crystallite size found to be in the range of 10 to 36 nm. The thick films of undoped ZnO and Al2O3 doped-ZnO were prepared by screen printing technique. The surface morphology of the films was studied by SEM and it shows the films are porous in nature and petal-shaped grains of sizes varies from 190nm to 276nm were observed. The final composition of each film was determined by EDAX analysis. The At. wt. % of Zn and O in each sample was not as per stoichiometric proportion. The electrical conductivity and activation energy of all films were determined.