The Correlation of Miller Indices with the Conductivity Mechanism of Cu-Based High-Tc Superconductor

Abstract

The high temperature superconductor of CuBa 2 Ca 2 Cu 3 O 8+ δ (Cu-1223) was synthesized experimentally by solid-state reaction. There were many pa-rameters affecting the preparation technique such as oxygen flow, sintering temperature, sintering time, and compacted pressure. The XRD-pattern exhibited a tetragonal phase for both Cu-1223, and Cu-1212. The resistivity measurement was considered the important experiment to show the predominant phase of superconductor if it was a high phase or low phase. The critical temperature (T c ) was about (128 K) for the high phase of Cu-1223, whereas the low phase of (Cu-1212) appeared at (T c = 64 K). The correlation between the Miller indices and resistivity measurements was a good tool to predicate the expected mechanism of conductivity within the unit cell. It was clear that the arrangement of these planes was aligned in the a-c direction. That should make the motion of the charge to be simpler by a stepping plane toward c-axis.