Abstract
High-resolution x-ray diffraction data show that the low-temperature superstructure of has an F-centered orthorhombic superlattice. A structure model is proposed, that is characterized by layers with zigzag charge order on all ladders and stacking disorder, such that the averaged structure has space group This model is in accordance with both x-ray scattering and NMR data. Variations in the stacking order and disorder offer an explanation for the recently observed devil’s staircase of the superlattice period along c.
- Received 3 August 2001
DOI:https://doi.org/10.1103/PhysRevB.65.060101
©2002 American Physical Society