Investigation of structural, dielectric, impedance and leakage current behaviour of green phase of yttrium barium copper oxide:Y2BaCuO5.

Comprehensive study of structural, dielectric, electrical, and ferroelectric characteristics of Yttrium Barium Copper Oxide (Y 2 BaCuO 5) ceramic, (accompanying phase of high-Tc superconductor YBa 2 Cu 3 O 7-X can unravel plethora of fascinating applications. Y 2 BaCuO 5 green phase cuprate has been prepared by employing ceramic fabrication technology. Room-temperature X-ray diffraction data of the polycrystalline sample suggests that it crystallizes in orthorhombic system in non-centrosymmetric Pbn2 1 spacegroup. The microstructure and elemental composition clearly illustrated by SEM micrograph and EDAX data. Frequency dependence of dielectric parameter has been discussed using Maxwell-Wagner model. Grain and grain boundary effects discussed using Nyquist plots; fitted to RQC and RC-RQC circuits. Temperature and Frequency dependent conductivity behaviour are explained using Arhenius equation and Jonscher power law. NSPT and CBH model of charge transport mechanisms observed. (I–V) charecteristics demonstrates semiconductor behaviour of Y 2 BaCuO 5 and its suitability for rectifier applications. Existence of hysteresis loop at room and high temperature up to 200 °C suggests ferroelectricity in Y 2 BaCuO 5. • Y 2 BaCuO 5 , a promising rare-earth cuprate, synthesized using cost-effective ceramic fabrication technique. • The green phase cuprate crystallizes in the non-centrosymmetric space group Pbn2 1 of orthorhombic crystal system. • Structural and microstructural analysis carried out using X-ray, SEM and EDAX. • Maxwell-Wagner polarisation effect along with various conduction mechanisms like CBH and NSPT observed in this compound. • Impedance spectroscopy (nyquist plot) of the sample suggests contribution of both Bulk and interface effects. • I-V charecteristics and leakage current behaviour suggest semiconducting behaviour of the sample. [ABSTRACT FROM AUTHOR]