An elastic neutron-scattering study has been performed on several single crystals of (formula presented) for x near a lower critical concentration (formula presented) for superconductivity. In the insulating spin-glass phase (formula presented) and 0.053), the previously reported one-dimensional spin modulation along the orthorhombic b axis is confirmed. Just inside the superconducting phase (formula presented) however, two pairs of incommensurate magnetic peaks are additionally observed corresponding to the spin modulation parallel to the tetragonal axes. These two types of spin modulations with similar incommensurabilities coexist near the boundary. The peak width (formula presented) along the spin-modulation direction exhibits an anomalous maximum in the superconducting phase near (formula presented) where the incommensurability (formula presented) increases monotonically upon doping across the phase boundary. These results are discussed in connection with the doping-induced superconducting phase transition.
|Number of pages||7|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2002|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics