The Simulation on the Phase Formation of Bi-Ba-Ca-Cu-O high Temperature Superconductor

The high-temperature superconductor like Bi۲Ba۲Ca۲Cu۳O۱۰+d was prepared using the solid-state reaction method at different calcination temperatures including ۷۸۰, ۸۰۰, and ۸۵۰ °C. X-ray diffraction technique was used to define crystal structure formation as a function of calcination temperature. It was found a tetragonal phase was obtained with lattice constants of a=b=۴.۲۹۶۷, and c=۳۶.۵۲۴۸ Å. It was found that there is a limited difference in the scattered peak intensities making a partial variation in the fraction volume of the phase formation. Such that the volume fraction of a high phase superconductor recorded ۷۳.۷۶% for the Bi-۲۲۲۳ phase at calcination temperature of ۸۰۰ °C. There is high intensity for the most probable peaks in the prepared sample at a temperature of ۸۰۰ °C mentioned by peaks (۰۱۰), (۱۱۰), and (۰۱۱۶) related to the tetragonal phase. Their intensities were twice incomparable with the peaks that appeared at calcination temperature at around ۸۵۰ °C. That is returned to high tetragonally and high stability in the atomic distribution within the unit cell. The structure simulation was applied due to the experimental X-ray patterns to investigate the formation of tetragonal shape via a unit cell. A Williamson-Hall method was used to show the crystallite size and the possible strain in the unit cell. It was found the lowest value of strain about (۰.۰۰۰۵) appeared at calcination temperature of ۸۰۰ °C. SEM and EDS had accomplished the surface morphology and elements concentration, their results were confirmed with XRD analysis .

کلیدواژه ها:

X-ray diffraction ، Williamson-Hall measurements ، Calcination temperatures ، High-temperature superconductor