Growth of the Dysprosium–Barium–Copper Oxide Superconductor Nanoclusters in Biopolymer Gels

Abstract

Clusters of DyBa₂Cu₃O_7−y high T_C type II nanosuperconductor were prepared by sol–gel method in the presence of biopolymer chitosan. At the first step, the precursor and biopolymer were aggregated into amorphous matrix and then hydrogels were formed by thermogelling. Nucleation and growth of discrete nanoparticles is controlled by the biopolymer gel owing to retention of the fibrous nature of the chitosan at high temperatures up to 500 °C. After heating to 900 °C and complete decomposition of BaCO₃, nanoparticles of DyBa₂Cu₃O_7−y superconductor with diameter of 10–20 nm in the form of nanoclusters are prepared. Critical temperature (T_c) of the nanoparticles was found to be above 83 K. Characterizations of specimens were performed using scanning electron microscopy and transmission electron microscopy, supported by other techniques including XRD diffraction, energy dispersive X-ray, FT-IR spectrum and magnetic susceptibility measurements.