Tunable structural and electrical impedance properties of pyrochlores based Nd doped lanthanum zirconate nanoparticles for capacitive applications

摘要

Pyrochlore structure based compounds have shown valuable interest in practical applications because of their structure tunability and stability. In this context, the stability of pyrochlore structure in a particular phase is quite essential for practical optimization of valuable dielectric and impedance characteristics of rare-earth zirconates. Thus, in the present work, a series of Nd substituted lanthanum zirconates were synthesized to investigate its effect on the structural, morphological, electrical and dielectric properties. Structural analysis confirmed the formation of sustainable pyrochlore phase in all the samples having space group Fd3m. A drastic reduction in grain size with Nd substitution was visualized by the images obtained using a field-emission scanning electron microscope. The electrical impedance spectroscopy was performed to check the frequency response of the dielectric behaviour, giving tenable information about changes in electrical permittivity due to Nd substitution. Impedance analysis shows a contribution of grains and grain boundaries in these heterogeneous zirconate samples. These regions are easily distinguishable in the sense of their electrical conductivity and impedance characteristics. The conductivity values obtained were lying in the range of nano-Farad predicted these materials to be used as solid oxide fuel cells.