Structural analysis of the [RE.sub.3][Ba.sub.5][Cu.sub.8][O.sub.18]

In this paper, we report the synthesis and structural characterization of the [RE.sub.3][Ba.sub.5][Cu.sub.8][O.sub.18] (RE = Dy, Gd, Ho, Sm, Y, Yb) system, which adds to the findings reported by Aliabadi, et al., who determined a critical temperature ([T.sub.C]) of ~ 100 K for the superconducting [Y.sub.3][Ba.sub.5][Cu.sub.8][O.sub.18] system and evaluated its structural response in a sample. The new [RE.sub.3][Ba.sub.5][Cu.sub.8][O.sub.18] system was produced using the solidstate reaction method and a similar thermal process as the one used for the superconductor RE: 123. The experimental results obtained with X-ray diffraction and the Rietveld analysis showed that these samples had the expected crystal structure. However, it was obvious that the presence of non-superconducting phases did not affect the superconducting transition temperature. Moreover, magnetic studies revealed that [RE.sub.3][Ba.sub.5][Cu.sub.8][O.sub.18] samples showed a superconductivity transition within a temperature range of 80 - 93 K depending on the rare earth.