across a global metal-insulator transition*

Motivated by the prediction of quantum critical behavior with the suppression of the temperature dependent metal-insulator transition in Ln₂Ir₂O₇ (Ln = Y, lanthanide), including the formation of a topological semi-metal phase^1,2, we present characterization of polycrystalline samples for the series (Eu_1-xCa_1-x)₂Ir₂O₇. Doping completely suppresses the MIT with only a weak decrease in the magnetic transition, leading to a fully metallic state that retains the bulk magnetism of the x = 0 compound. XRD and XAS suggest that the change of T_MIT occurs due to an interplay between bandwidth tuning via a change in the Ir-O-Ir bond angle as well as filling control. X-ray PDF shows no changes in short-range order associated with either the MIT or the magnetic transition, additionally confirming that Ca-doping does not result in significant phase separation. Preliminary XMCD data probing the magnetic state across the MIT will be discussed.”_.
1. L. Savary et al. Phys. Rev. X 4, (2014)
2. X. Wan et al. Phys. Rev. B 83, (2011)