SUPERCONDUCTIVITY IN SINGLE-CRYSTALS OF THE NONPEROVSKITE-LIKE CUPRATE BA2CU3O6-X

Spontaneous crystallization from a solution in a melt at a pressure of (0.8-1)x 10(-3) Pa was used to obtain single crystals of a new nonper ovskite-like superconducting phase Ba2Cu3O6-x (space group P-ccm a=13. 065, b=20.654, and c=11.431 Angstrom). The superconducting properties of the crystals were investigated by modulated microwave absorption. T he superconducting transition temperatures were 5 K (sample No. 1), 7 K and 13 K (sample No. 2). The superconductivity in the Ba2Cu3O6-x cry stals is attributed to the presence of CuO2 chains of edge-sharing cop per-oxygen squares. Nonperovskite-like Ba2Cu3O6-x crystals are a new c lass of one-dimensional (1D) superconductors. (C) 1997 American Instit ute of Physics.