  Strong spin-orbit coupled 5d transition metal based ABO3 oxides, especially
iridates, allow tuning parameters in the phase diagram and may demonstrate
important functionalities, for example, by means of strain effects and
symmetry-breaking, because of the interplay between the Coulomb interactions
and strong spin-orbit coupling. Here, we have epitaxially stabilized high
quality thin films of perovskite (Pv) CaIrO3. Film on the best lattice-matched
substrate shows semi-metal-like characteristics. Intriguingly, imposing tensile
or compressive strain on the film by altering the underlying lattice-mismatched
substrates still maintains semi-metallicity with minute modification of the
effective correlation as tensile (compressive) strain results in tiny increases
(decreases) of the electronic bandwidth. In addition, magnetoresistance remains
positive with a quadratic field dependence. This persistent semi-metal-like
nature of Pv-CaIrO3 thin films with minute changes in the effective correlation
by strain may provide new wisdom into strong spin-orbit coupled 5d based oxide
physics.
