title: Persistent non-metallic behavior in Sr2IrO4 and Sr3Ir2O7 at high pressures.
abstract: Iridium-based 5d transition-metal oxides are attractive candidates for the study of correlated electronic states due to the interplay of enhanced crystal-field, Coulomb and spin-orbit interaction energies. At ambient pressure, these conditions promote a novel Jeff = 1/2 Mott-insulating state, characterized by a gap of the order of ~0.1 eV. We present high-pressure electrical resistivity measurements of single crystals of Sr2IrO4 and Sr3Ir2O7. While no indications of a pressure-induced metallic state up to 55 GPa were found in Sr2IrO4, a strong decrease of the gap energy and of the resistance of Sr3Ir2O7 between ambient pressure and 104 GPa confirm that this compound is in the proximity of a metal-insulator transition.
authors.forename: D A
authors.initials: DA
authors.lastname: Zocco
authors.forename: J J
authors.initials: JJ
authors.lastname: Hamlin
authors.forename: B D
authors.initials: BD
authors.lastname: White
authors.forename: B J
authors.initials: BJ
authors.lastname: Kim
authors.forename: J R
authors.initials: JR
authors.lastname: Jeffries
authors.forename: S T
authors.initials: ST
authors.lastname: Weir
authors.forename: Y K
authors.initials: YK
authors.lastname: Vohra
authors.forename: J W
authors.initials: JW
authors.lastname: Allen
authors.forename: M B
authors.initials: MB
authors.lastname: Maple