MORPHOLOGY OF GROWTH OF BI2SR2CACU2O8 SINGLE-CRYSTALS

A good correlation of twins on the basal surface of put-grown Bi2Sr2Ca Cu2Ox (BSCCO) single crystals with surface growth steps is observed, t he b-axis being perpendicular to the steps and, thus, parallel to the growth direction. A is found that mono-twin BSCCO single crystals prod uced by the travelling solvent floating zone method also grow preferen tially along b, i.e. nearly perpendicularly to the boule axis, contrar y to the common belief. This new understanding of the morphology, of g rowth explains the nature of major defects in these crystals, which co nsiderably change their measured superconducting properties, in a diff erent way.