The crystal structure of the high-Tc superconducting phase Ba2YCu3O9-(=2.0) has been determined by single-crystal x-ray diffraction. The compound crystallizes in an orthorhombic, oxygen-deficient perovskite superstructure with space group Pmmm, a=3.856(2) A b=3.870(2) A, and c=11.666(3) A. The ordering of Ba and Y in a [Ba-Y-Ba] sequence along the c axis is responsible for the tripled cell. Two [CuO2] planes with copper in distorted square planar coordination are the key to conductivity.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics