Improvement of the Superconducting Properties of Ho۱۲۳ Nanoparticles via a Polymer Mediated Sol-Gel Method

چکیده مقاله

Superconducting nanoparticles, HoBa2Cu3O7−x, was successfully synthesized by protecting in a biopolymeric ethyl cellulose template. The embedded nanoparticles in the amorphous matrix of ethyl cellulose form the isolated site for outgrowth of Ho123 nanoparticles assemblies after breakdown of the polymer at temperatures above 500 ◦C, according to Fourier transform infrared (FT-IR) spectra. Transmission electron microscope (TEM) and scanning electron microscopy (SEM) showed that the nanoparticles with uniform size less than 40 nm in the form of thin sheets with diameters in the range of 80 to 100 nm can be readily formed by controlling the concentration of the biopolymer. Structural analysis confirmed a pure and single phase of orthorhombic structure. By comparing to bulk materials, it was found that decreasing the particle size had no significant effect on the onset of superconductivity in the nanoparticles.