Defect generation by preferred nucleation in epitaxial Sr2RuO4/LaAlO3Sr2RuO4/LaAlO3

The atomic structure of the film–substrate interface of a (001) Sr2RuO4/(100)c LaAlO3Sr2RuO4/(100)cLaAlO3 film, determined by high-resolution transmission electron microscopy and simulation, is reported. The structure of superconductivity-quenching Δc ≈ 0.25 nmΔc≈0.25nm out-of-phase boundaries (OPBs) in the film is also reported. Growth in one region on the La-terminated surface is observed to nucleate with a SrO layer. Because two structurally equivalent SrO layers exist within the unit cell, two neighboring nuclei with differing growth order (SrO-RuO2-SrO(SrO-RuO2-SrO or RuO2-SrO-SrO)RuO2-SrO-SrO) will nucleate an OPB where their misaligned growth fronts meet. Strategies to avoid OPB generation by this mechanism are suggested, which it is hoped may ultimately lead to superconducting Sr2RuO4Sr2RuO4 films. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69525/2/APPLAB-83-19-3891-1.pd