Single crystal X-ray characterization of the incommensurate modulation in the high Tc superconductor Bi2Sr 2CaCu2O8.

Abstract
We have studied the incommensurate modulation in Bi2Sr 2CaCu2O8 by single crystal X-ray diffraction. First and second order satellite reflections with wave vectors q1 = (0,0.211,1) and q2 = 2q1 have been measured. The period of the modulation along b is 25.59 Å. A preliminary analysis of the satellite intensities indicates that the modulation involves strong displacive components polarized along b and c. No low-temperature changes have been observed. The single crystals exhibit a large systematic mosaicity