1212.5912 (S. Boseggia et al.)

Robustness of basal-plane antiferromagnetic order and the $J_{eff}=1/2$
state in single-layer iridate spin-orbit Mott insulators    [PDF]

S. Boseggia, R. Springell, H. C. Walker, Ch. Rüegg, H. Okabe, M. Isobe, R. S. Perry, S. P. Collins, D. F. McMorrow

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 $L_3/L_2$ intensity ratio, is consistent with a $J_{eff}=1/2$ 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.

View original: http://arxiv.org/abs/1212.5912