For the Sr2-xIrO4 system, recent work pointed out the abnormal electronic and magnetic properties around the critical point. Here, to understand Sr-vacancy effect on spin-orbit coupled Mott insulator Sr2IrO4, the electronic structure and local structure distortion for Sr2-xIrO4 system have been investigated by x-ray absorption spectroscopy (XAS). By comparing the intensity of white-line features at the IrL2,3-edge x-ray absorption near-edge spectroscopy (XANES), we observe a sudden rise of the branching ratio in the vicinity of the critical point.Further analysis on theIrL3 -edge extended x-ray absorption fine structure (EXAFS) and calculated data demonstrated that the abrupt enhancement of the branching ratio is intimately related to the less distorted IrO6 octahedra induced by deep Sr-vacancies, which in turn alters the relatively strength of the spin-orbit coupling (SOC) and crystal electric field (CEF)that would dictate the abnormal behavior of electronic and magnetic structure near the critical point.
@article{arxiv.1610.09817,
title = {A critical point in Sr2-xIrO4 and less distorted IrO6 octahedra induced by deep Sr-vacancies},
author = {Jie Cheng and Shengli Liu and Bin Li and Haiyun Wang and Yu Wang and Wei Xu},
journal= {arXiv preprint arXiv:1610.09817},
year = {2019}
}
Comments
18 pages, 5 figures. arXiv admin note: text overlap with arXiv:1610.09839