화학공학소재연구정보센터
Particulate Science and Technology, Vol.33, No.1, 41-46, 2015
AC and DC Conductivity Studies on Lead-Free Ceramics: Sr1-xCaxBi4Ti4O15(x=0, 0.2, 0.4, 0.6, 0.8)
Sr1-xCaxBi4Ti4O15 [x=0, 0.2, 0.4, 0.6, 0.8] ceramics are synthesized by solid-state reactive technique. Structural analyses are done by x-ray diffraction data. Morphological studies were carried out by scanning electron microscope, and the data showed plate-like structures. To understand the conductivity mechanism, frequency and temperature dependency of AC and DC conductivity studies are carried out. The conductivity measurements are done using an impedance analyzer (Wayn-Kerr) in the temperature range 100-600 degrees C. The frequency-dependent AC conductivity at different temperatures indicates that the conduction process follows the universal power law, and the hopping frequency shifts toward higher frequency side with increase in temperature, below which the conductivity is frequency independent. The variation of DC conductivity confirms that the ceramics exhibit negative temperature coefficient of resistance behavior at high temperature. DC conductivity values do not show any linearity with doping concentration; for a particular composition SCBT06, the DC conductivity was low.