Abstract
We report a single-crystal neutron diffraction study of the layered . This work unambiguously determines the magnetic structure of the system and reveals that the spin orientation rigidly tracks the staggered rotation of the octahedra in . The long-range antiferromagnetic order has a canted spin configuration with an ordered moment of 0.208(3) /Ir site within the basal plane; a detailed examination of the spin canting yields 0.202(3) and 0.049(2) /site for the axis and the axis, respectively. It is intriguing that forbidden nuclear reflections of space group are also observed in a wide temperature range from 4 K to 600 K, which suggests a reduced crystal structure symmetry. This neutron-scattering work provides a direct, well-refined experimental characterization of the magnetic and crystal structures that are crucial to the understanding of the unconventional magnetism exhibited in this unusual magnetic insulator.
- Received 11 February 2013
DOI:https://doi.org/10.1103/PhysRevB.87.140406
©2013 American Physical Society