الفهرس 
Theoretical considerationsOnly 14 pages are availabe for public view
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Abstract
Ba.rhn titanate has been used as a lnultilayer ceramic capacitor due to its high dielectric constant and low dielectric loss. The aim of the present work is to investigate the effect of lanthanum oxide (La, 0 3) and niobium oxide (Nb , 0 - ) -7 additives on the physical properties of the ceramic BaTi03. Samples were prepared, using the ceramic technique, to obtain the coinposition BaTi03 -La203 -Nb205 (with Nb205 =O.lwt% and La20, =0.0,0.1, 0.2,0.3 aid 0.4). The investigation included the study of the effect of La substitution and temperature on various properties. The stnlcture of the samples have been confinned by X-ray diffraction showing that beside the main tetragonal phase, there is a new phases due to the inhomogeneity ofthe dopants during preparation method. The lattice parameter, the density, X-ray density and porosity are determined as a functions of composition. The &electric constant have been measured in a wide range of temperature from room temperature to 200 ”C for all compositions at constant frequency 1 KHz, also dielectric loss have been measured at the same frequency (1 KHz) from room temperature to 160 ” C. D. C. Resistivity have been measured in the temperature range 60 - 200 ” C