Temperature and Frequency Dependence of Dielectric Properties of Superconducting Ceramic GdBa2Ca3Cu4O10.5

A polycrystalline, superconducting ceramic GdBa2Ca3Cu4O10.5 having nano sized particles is designed, and prepared by solid state reaction route involving selection of raw materials, mixing, manual milling, ball milling, calcining at treating temperatures and sintering. Prepared ceramic is found to be in perovskite structure and in orthorhombic crystal system by X ray diffraction and related studies. Dielectric behaviour of the ceramic is studied observing the effects of temperature and frequency on some important dielectric parameters such as dielectric constant, dielectric loss, impedance and conductivity. High impedance and high dielectric constant in low frequency and high temperature regions are expected in the case of superconducting ceramics. Dielectric parameters should be reduced with increasing frequencies and decreasing temperatures and saturation values should be reached. Dielectric studies are conducted in a selected frequency range with in 42Hz-5MHz, at three different temperatures 300C, 5000C and 9000C in a frequency response analyzer which is connected with a computer and a heating arrangement. Impedance spectroscopic studies and conductivity studies are also done. Debye relaxation behaviour, space charge polarization and Maxwell Weigner model of low frequency dielectric dispersion (LFDD) are observed in the sample. Conductivity is found to obey, Jonschers power law of conductivity.