TEM ANALYSIS OF PLANAR DEFECTS INDUCED BY TI DOPING IN BI-2212 SINGLE-CRYSTALS

An electron microscopy study is performed on Ti doped Bi-2212 single c rystals. High resolution electron microscopy reveals that the Ti dopin g leads to incorporation of (010) planar defects in the Bi-2212 lattic e. These defects consist of pairs of antiphase boundaries, which are s eparated along the b-axis by one modulation distance. The atomic shift at the boundary is such that one of the two CuO2, planes is continuou s throughout the defect. Energy dispersive X-ray analysis clearly reve als the presence of Ti in the planar defects, whereas no Ti could be d etected in defect free areas. This evidences the fact that these defec ts are induced by the Ti doping. (C) 1997 Elsevier Science B.V.