title: The electronic structure of epitaxially stabilized 5d perovskite Ca(1-x)Sr(x)IrO3 (x = 0, 0.5, and 1) thin films: the role of strong spin-orbit coupling.
abstract: We have investigated the electronic structure of meta-stable perovskite Ca(1 - x)Sr(x)IrO(3)(x = 0, 0.5, and 1) thin films using transport measurements, optical spectroscopy, and first-principles calculations. We artificially fabricated the perovskite phase of Ca(1 - x)Sr(x)IrO(3), which has a hexagonal or post-perovskite crystal structure in bulk form, by growing epitaxial thin films on perovskite GdScO(3) substrates using an epi-stabilization technique. The transport properties of the perovskite Ca(1 - x)Sr(x)IrO(3) films systematically change from nearly insulating (or semi-metallic) for x = 0 to weakly metallic for x = 1. Due to the extended wavefunctions, 5d electrons are usually delocalized. However, the strong spin-orbit coupling in Ca(1 - x)Sr(x)IrO(3) results in the formation of effective total angular momentum J(eff) = 1/2 and 3/2 states, which puts Ca(1 - x)Sr(x)IrO(3) in the vicinity of a metal-insulator phase boundary. As a result, the electrical properties of the Ca(1 - x)Sr(x)IrO(3) films are found to be sensitive to x and strain.
authors.affiliation: ReCFI, Department of Physics and Astronomy, Seoul National University, Seoul, Republic of Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Jang
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: S J
authors.initials: SJ
authors.lastname: Moon
authors.forename: W S
authors.initials: WS
authors.lastname: Choi
authors.forename: B C
authors.initials: BC
authors.lastname: Jeon
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.forename: T W
authors.initials: TW
authors.lastname: Noh