Publications

In the search for highly responsive dielectric materials, superconducting samples of type (Bi,Pb)-2223 were prepared using the standard solid-state reaction technique, with the addition of three different concentrations of ferrato and mangano-undecatungstosilicate (0.04, 0.12, and 0.20 wt%). The dielectric studies were performed by measuring the parallel capacitance Cp as well as the dielectric loss factor using LCR HiTESTER. The studies were performed at temperature and frequency ranges starting from room temperature down to 98 K and from 50 kHz up to 5 MHz, respectively. The dielectric behavior was investigated by calculating both dielectric constants (ε′ and ε′′), loss tangent (Tanδ) and ac conductivity (σac) as a function of frequency, temperature and addition concentrations of the {FeSiW11} and {MnSiW11} polyoxometalates. The results revealed that the dielectric parameters decrease with increasing frequency at each temperature for all the {FeSiW11}x(Bi,Pb)-2223 and {MnSiW11}x(Bi,Pb)-2223 prepared samples. Moreover, ε′ and σac showed a decreasing trend with an increase in temperature in contrast to the increasing trend shown by ε′′ and Tanδ. Additionally, ε′′ has decreased upon increasing temperature at low frequencies. Accordingly, low {MnSiW11} addition at 0.12 wt% exhibited the highest dielectric constant (1.99×107) and ac conductivity 61.449 (Ω.m)−1 with minimum dissipation (1.078). Furthermore, the ac conductivity was studied according to the power law, and the frequency exponent was found greater than one (1.654≤S≤1.759) for all the prepared samples.