Abstract
The effect of sintering temperature and grain size on the electrical transport properties of lanthanum-based manganite, La0.67Sr0.33MnO3, was investigated by impedance spectroscopy technique. The sintering temperature was varied from 600 degrees C to 1000 degrees C. From dc-conductivity analysis, it is found that increasing sintering temperature improved the electrical conductivity and does not change the value of the temperature of metal-semiconductor transition. Such results have been explained in terms of core-shell model. The presence of relaxation phenomenon in the material was detected by complex impedance analysis. Also, such analysis confirms the contribution of grain boundary in the electrical properties of the lanthanum-manganite. (C) 2015 Elsevier B.V. All rights reserved.