المستخلص: |
Ceramic dielectric of undoped BaTiO3(BT), 3wt%Na2CO3-doped BaTiO3 (BTNa3) and 5wt%Na2CO3-doped BaTiO3 (BTNa5) compositions were prepared by the solid State reaction method .All coposition were sintered at 1350 ºC for 4hrs. the crystal structure of compositions were identified by using X-ray diffraction. Silver paste electrodes were used for electrical measure on opposite surfaces of specimens at 300ºC for 1.5 hrs. the temperature dependence of relative permittivity and loss tangent at fixed frequency (1KHz) were measured over a temperature range spanning tetragonal and cubic phases. The activation energies were calculated from Arrhenius plot (ln(σT) vs of all compositions. The curie constant and the phase transition points for all compositions were calculated from curie weiss relation plot [(1/εr) vs T ] as shown in figures(6-a,b,c) compined with table(2)
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