Synthesis and sintering characteristics of Y–Ba–Cu-oxide superconductors

Abstract

Y–Ba–Cu-Oxide (YBCO) powder were prepared by three different techniques and the isothermal sintering characteristics of the synthesized powder were systematically investigated using a thermo-mechanical analyzer (TMA). Expectedly the apparent densities of the sintered samples increased with the decrease of particle sizes of the synthesized powder due to high specific surface energy. The nano-sized powder generated by a chemical pyrophoric reaction exhibited excellent sinterability than the powder synthesized by either the conventional ceramic process (CCP) or the co-precipitation process (CP). The variation of apparent activation energies for sintering (Q) and sintering kinetic parameter (n) with the change of particle sizes of the green compacts indicated differing nature of mass transport phenomena operating in the system during sintering. The apparent activation energies for sintering were estimated from the respective Arrhenius plots.