Influence Of Sample Microstructures On The Decoration Pattern

Bitter decoration experiments were performed on melt-textured YBa2Cu3Oy, single-crystal YBCO and BiSrCaCuO samples at 36K in an external magnetic field of 25G. A flux line density gradient was observed from the edge to the centre of the single crystal YBCO sample. In melt-textured YBCO samples ferromagnetic particles mainly concentrate on the regions of strong pinning. However, no Bitter-patterns were found on the surfaces of BiSrCaCuO single crystals.