The magnetic structure and electronic groundstate of the layered perovskite Ba2IrO4 have been investigated using x-ray resonant magnetic scattering (XRMS). Our results are compared with those for Sr2IrO4, for which we provide supplementary data on its magnetic structure. We find that the dominant, long-range antiferromagnetic order is remarkably similar in the two compounds, and that the electronic groundstate in Ba2IrO4, deduced from an investigation of the XRMS L3/L2 intensity ratio, is consistent with a Jeff=1/2 description. The robustness of these two key electronic properties to the considerable structural differences between the Ba and Sr analogues is discussed in terms of the enhanced role of the spin-orbit interaction in 5d transition metal oxides.
@article{arxiv.1212.5912,
title = {Robustness of basal-plane antiferromagnetic order and the $J_{eff}=1/2$ state in single-layer iridate spin-orbit Mott insulators},
author = {S. Boseggia and R. Springell and H. C. Walker and Ch. Rüegg and H. Okabe and M. Isobe and R. S. Perry and S. P. Collins and D. F. McMorrow},
journal= {arXiv preprint arXiv:1212.5912},
year = {2013}
}