X-ray, neutron-, and electron diffraction study of the incommensurate structure in single cystals of Bi2.2Sr1.9CaCu2O8+x.

Abstract

We have used x-ray, neutron, and electron diffraction to study the incommensurate structure in superconducting single crystals of ${\mathrm{Bi}}_{2.2}{\mathrm{Sr}}_{1.9}\mathrm{Ca}{\mathrm{Cu}}_{2}{\mathrm{O}}_{8+x}$ at 300 K. Large differences between relative x-ray and neutron superlattice intensities imply a large oxygen contribution to the modulation. While the positions of the superlattice peaks are symmetric in ${Q}_{H}$ and ${Q}_{K}$ about the sublattice (020) reflection, the intensities are not. This probably rules out a sinusoidal one-dimensional mass density wave interpretation.