Diffuse streaks centered at q=(0,(2/5,0) and (0,(1/2,0) have been observed in annealed Ba2YCu3O7- with 0.30.4, which has a Tc of 60 K and a Meissner effect equivalent to the 90 K phase. We interpret the presence of the diffuse streaking as a result of short-range oxygen vacancy ordering. The vacancy ordering has a short correlation length along the copper-oxygen chains (b direction) and a long correlation length perpendicular to the chains along the a direction. The ordered structure is completely uncorrelated parallel to the c axis.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics