Abstract
Powder neutron diffraction studies of undoped have revealed new superlattice peaks below ∼220 K. The absence of corresponding x-ray superlattice lines and an observed susceptibility anomaly near 220 K suggest the occurrence of antiferromagnetism. From the magnetic peak intensities we deduce a structure consisting of ferromagnetic sheets of Cu spins alternating along the [100] orthorhombic axis, with the spins aligned along the [001] orthorhombic axis, The low-temperature magnetic moment is approximately 0.5/(Cu atom). The tetragonal-orthorhombic transition at 505 K has also been studied.
- Received 4 May 1987
DOI:https://doi.org/10.1103/PhysRevLett.58.2802
©1987 American Physical Society