Structural, microstructural and dielectric behavior of sol–gel grown nanostructured Y0.95Zr0.05MnO3

Abstract

In this communication, we report the results of the studies on structural, microstructural and dielectric properties of nanostructured Y0.95Zr0.05MnO3 (YZMO) manganites synthesized by acetate precursor route based sol–gel method. Effect of sintering temperature and hence crystallite size on the room temperature dielectric behavior has been discussed on the basis of boundary density and electric phase coexistence. Temperature dependent dielectric vs. frequency behavior of all nanostructured YZMO suggests ferroelectric nature of the samples without any dielectric anomaly within the temperature range studied. Structural studies have been carried out by performing X–ray diffraction (XRD) measurements using CuKα X–ray source. Transmission electron microscopy (TEM) images reveal an increase in particle size with sintering temperature while for all the three samples understudy particles are grown with sharp particle boundaries. Particle size analyzer study shows a broad size distribution for the lower temperature sintered samples. Dielectric constant is found to decrease with sintering temperature for all the samples. Cole–cole plots have been studied for the relaxation mechanisms while various mechanisms, theories and models have been discussed to understand the dielectric behavior of the samples. Capacitance of the samples has been discussed in the context of electric phase coexistence, built–in potential and free charge carrier density.