Neutron diffraction measurements are presented exploring the magnetic and structural phase behaviors of the candidate Jeff=1/2 Mott insulating iridate Sr2IrO4. Comparisons are drawn between the correlated magnetism in this single layer system and its bilayer analog Sr3Ir2O7 where both materials exhibit magnetic domains originating from crystallographic twinning and comparable moment sizes. Weakly temperature dependent superlattice peaks violating the reported tetragonal space group of Sr2IrO4 are observed supporting the notion of a lower structural symmetry arising from a high temperature lattice distortion, and we use this to argue that moments orient along a unique in-plane axis demonstrating an orthorhombic symmetry in the resulting spin structure. Our results demonstrate that the correlated spin order and structural phase behaviors in both single and bilayer Srn+1IrnO3n+1 systems are remarkably similar and suggest comparable correlation strengths in each system.
@article{arxiv.1212.1489,
title = {Neutron scattering study of correlated phase behavior in Sr2IrO4},
author = {Chetan Dhital and Tom Hogan and Z. Yamani and Clarina de la Cruz and Xiang Chen and Sovit Khadka and Zhensong Ren and Stephen D. Wilson},
journal= {arXiv preprint arXiv:1212.1489},
year = {2013}
}