ELECTRICAL CONDUCTIVITY OF CERAMIC BODIES WITH ZnO OR MnO ADDITIONS

R. M. Mahani, D. A. Abdel Aziz, A. E. Reda

Abstract


The present research is an attempt to develop the indigenous technology requiring the utilization of the low cost local raw materials. Egyptian raw material such as nepheline syneite and clays were used with the same proportions (50 wt. % for each) for producing ceramics whose electrical resistivity is comparable with that reported for porcelains. Zinc oxide (ZnO) and manganese oxide (MnO) with 2 and 5 wt. % were individually added to make the chemical reaction occurs faster with less energy and also to improve the electrical insulation properties of the ceramics. X - ray diffraction and scanning electron microscope were used to characterize the crystalline phases and microstructure of the ceramic bodies, respectively. The dielectric measurements were carried out by means of dielectric spectroscopy over frequency range (102 to 106 Hz) at temperature range (25 - 275 C). The ceramic electrical conductivity exhibited strongly additives dependence since its values significantly decreased (resistivity increase) upon adding either ZnO or MnO even at small amounts. This was attributed to the decrease of ions concentration due to their arrangements in specific ordered structures; zinc aluminates (ZnAl2O4) or manganese ferrite (MnFe2O4) upon adding ZnO or MnO, respectively. 

Keywords


Clay, Nepheline Syenite, ZnO, MnO, Dielectric properties, Ceramics

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