Growth of high-quality perovskite (110)-SrIrO3 thin films using reactive molecular beam epitaxy

Recently, 5d transition metal iridates have been reported as promising materials for the manufacture of exotic quantum states. Apart from the semimetallic ground states that have been observed, perovskite SrIrO3is also predicted to have a lattice-symmetrically protected topological state in the(110) plane due to its strong spin–orbit coupling and electron correlation. Compared with non-polar(001)-SrIrO3, the especial polarity of(110)-SrIrO3undoubtedly adds the difficulty of fabrication and largely impedes the research on its surface states. Here, we have successfully synthesized high-quality(110)-SrIrO3thin films on(110)-SrTiO3substrates by reactive molecular beam epitaxy for the first time. Both reflection high-energy electron diffraction patterns and x-ray diffraction measurements suggest the expected orientation and outstanding crystallinity. A(1 × 2) surface reconstruction driven from the surface instability, the same as that reported in(110)-SrTiO3, is observed. The electric transport measurements uncover that(110)-SrIrO3exhibits a more prominent semimetallic property in comparison to(001)-SrIrO3.