Impedance and modulus spectroscopy characterization of La+3/Mn+4 modified PbTiO3 nanoceramics

Nanocrystalline samples of Pb0.92La0.08MnxTi1-xO3 (PLMT) (x = 0, 0.04, 0.07, 0.10) were prepared by a high-energy ball-milling followed by a solid-state reaction method. Preliminary high resolution X-ray diffraction technique of PLMT ceramics showed that a single-phase was formed exhibiting a tetragonal crystal structure. The electrical behavior of PLMT ceramics was investigated by the impedance spectroscopy in the temperature range of 35 °C–500 °C. This study was carried out by means of the simultaneous analysis of the complex impedance (Z∗) and electrical modulus (M∗) functions from the measurement range of 1 kHz–1 MHz. A separation of the grain and grain boundary properties has been achieved using an equivalent circuit model in impedance analysis. Loss spectra reveal about the presence of temperature-dependent electrical relaxation phenomena in the materials. Modulus analysis provides wider information related to charge transport processes.