Distribution of the satellite reflections of the modulation and its thermal stability in singlehyphen;crystal Bi2Sr2CaCu2Oy

摘要

The satellite distribution around the main reflections of the incommensurate modulation in Bi2Sr2CaCu2Oyhas been studied by means of xhyphen;ray diffraction on a number of single crystals. The presence of the forbidden reflections which are incompatible with aBhyphen;centered Bravais lattice is found to be correlated with the spread of the mosaic blocks in the crystal sheet and therefore spurious to the distribution of the satellite reflections in the reciprocal space. Diffraction data collected for a highly oriented crystal annealed in flowing nitrogen at 650thinsp;deg;C for 60 h have shown that the structural modulation is coherent with the Bi2Sr2CaCu2Oyphase and robust to the anneal. Relationships between superconductivity, structural modulation, and oxygen content in the compound are discussed.