Structural aspects of the spin-ladder compound Sr14Cu24O41

Single crystal neutron scattering measurements have been performed on the spin-ladder compound Sr14Cu24O41 at 7 K. The incommensurate composite structure has been determined using the superspace group formalism. The low-temperature structure does not show a significant shift of the CuO2 chains along the c direction. In addition to the main and satellite nuclear reflections compatible with the incommensurate composite structure, new weak super-structure peaks at Q = (hkL(c)), with L-c = n +/- 0.20 (+/-0.01) have been observed. Their origin is probably due to the charge ordering associated to a three-dimensional configuration of the spin dimers in the CuO2 chain. (C) 2004 Elsevier B.V. All rights reserved.