الفهرس 
Theoretical considerationsOnly 14 pages are availabe for public view
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Abstract
the present work is to study the physical and electrical properties of mixed ferrites for different compositions Col-, Zn, Fe204 where ( x = 0.0, 0.3, 0.4, 0.6, 0.8 and 1). The ceramic method is used to prepare the samples. They are pressed into disc form under constant pressure of about 4 tons/cm2 and finally sintered at 12000C for 2 hours. The materials prepared are identified by X-ray diffraction method, the lattice parameter is calculated. All compositions are found to have cubic spinel structure. Some physical properties such as density, porosity, electrical resistivity and thermoelectric power have been studied. Both resistivity and thermoelectric power have been studied under vacuum in a wide range of temperature from room temperature up to 6000K. The dielectric properties and a.c conductivity have been measured as a function of composition in the frequency range 20 c/s up to lo5 c/s at room temperature. Conclusions : 1 - The conductivity in ferrites is due to hopping conduction mechanism for electrons. 2- The measured density is less than the predicted from X-ray measurements and each of them increases with increasing the zinc content but the porosity decreases.