Crystal electric field and structural study of J<sub>eff</sub> = 1/2 K<sub>2</sub>IrX<sub>6</sub> (X = Cl, Br)
ORAL
Abstract
Strong spin orbit coupling in 5d materials has been a focus of research due to the wide variety of exotic phases which can exist in these systems. Of particular interest are systems with octahedral coordination, the triply degenerate t2g state will split into the occupied Jeff = 3/2 and the partially occupied Jeff = ½ states. It is this Jeff = ½ state that can host a large range of exotic phases such as quantum spin liquids and superconductivity. Here we present detailed data on two Iridium halide materials, K2IrX6, X = Cl, Br, which have the antifluorite structure and the Ir atom inside separated halide octahedra. Powder X-ray scattering study show a newly observed structural transition in the Br compound at Tc=180K. Resonant inelastic X-ray scattering data and X-ray absorption data are combined with quantum chemistry calculations to study the crystal electric field levels, and show that these materials show record proximity to the ideal Jeff = ½ state at all temperatures down to T=5K.
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*This work was supported by the National Science Foundation, grant number DMR-1455264-CAR.
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Presenters
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Dalmau Reig-i-Plessis
- University of Illinois at Urbana-Champaign