الفهرس 
Theoretical considerationsOnly 14 pages are availabe for public view
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Abstract
Yettrium oxide doped BaTiO, ceramic was prepared by the general 3 ceramic method to obtain the system The investigation included the study of the Y substitution, frequency and temperature on various properties. X-ray difiaction patterns confirmed the tetragonal structure of the undoped BaTi0 3, whle a complex phase was formed in the form of BaTi,O, - Y,03 for doped samples. It is observed that the D.C. electrical resistivity increases with increasing temperature up to certain temperatures wlich is due to introducing lattice vacancies. The increases of temperature increases the cation vacancies fiuthur more mion vacancies. The increase of the cation vacancies (Ba vacancies) decrease the anion vacancies and reduce the conductions electrons. The decrease of resistivity for T > 353K is due to the generation of exchange electrons between Ti4+ t- y3+ and T?+ - TP+ whch led to decrease the resistivity of the different compositioils with rising temperature. The slight increase of dielectric constant (E’) with rising temperature at f = lKHz is due to increasing the rate of hopping electrons between Ti3’ c=,~ iin ~the +direc tion of a.c. applied field leadmg to slight increase of the polarization with hgher temperatures. It is noticed from the results that the peak of dielectric constant &sappeared which is due to the fornation of complex