Abstract
In this study, the effects of (K6[(H2O)MnSiW11O39]·21H2O, {MnSiW11}) polyoxometalate, with an average particle size of 48.46 nm, on (Bi1.8Pb0.4)Ca2Sr2Cu3O10+δ (Bi,Pb)-2223, superconducting samples, were investigated. Samples of type {MnSiW11}x(Bi1.8Pb0.4)Ca2Sr2Cu3O10+δ, 0.00 ≤ x ≤ 0.20 (wt%) were prepared using the conventional solid-state reaction technique. Manganese-containing polyoxometalates are considered as an attractive class of inorganic nanomaterials, because they have multiple oxidation states and many unpaired electrons. Consequently, the microstructure, morphology, optical and magnetic properties of the prepared {MnSiW11} nanoparticles were determined by powder X-ray diffraction (XRD), transmission electron microscopy, Fourier transform infrared spectroscopy and magnetic hysteresis loop measurements, respectively. The bulk of superconducting samples was characterised by XRD, scanning electron microscopy and energy dispersive X-ray spectroscopy. The XRD analysis showed that the addition of small amounts of {MnSiW11} nanoparticles improves (Bi,Pb)-2223 phase formation significantly. The lattice parameters (a and c) of (Bi,Pb)-2223 phase did not change with the addition of nanoparticles. Furthermore, the superconducting transition temperature (Tc) was determined from dc electrical resistivity (ρ − T) as a function of temperature measurements. Tc was enhanced as x increased up to x = 0.12 wt%, then decreased gradually with a further increase in the concentration of nanoparticles. The ($$E$$ − $$J$$) measurements were conducted at 77 K with 1 μV/cm. It showed that the critical current density (Jc) of the samples increased from about 301.9 to 728.4 A/cm2 as x increased from 0.00 to 0.12 wt%. The suppression in Tc and Jc for x > 0.12 wt% samples may be due to the decrease in the volume fraction of a high-Tc (Bi,Pb)-2223 phase and the increase of weak links connectivity among the grain boundaries.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
