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

摘要

Recently, 5d transition metal iridates have been reported as promising materials for the manufacture of exotic quan-tum states. Apart from the semimetallic ground states that have been observed, perovskite SrIrO3 is 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)-SrIrO3 undoubtedly adds the difficulty of fabrication and largely impedes the research on its surface states. Here, we have successfully synthesized high-quality (110)-SrIrO3 thin films on (110)-SrTiO3 substrates by reactive molecular beam epitaxy for the first time. Both reflec-tion 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)-SrIrO3 exhibits a more prominent semimetallic property in comparison to (001)-SrIrO3.