Dynamic Interface Rearrangement in LaFeO${}_3$ / $n$-SrTiO${}_3$ Heterojunctions

Abstract

Thin film synthesis methods developed over the past decades have unlocked emergent interface properties ranging from conductivity to ferroelectricity. However, our attempts to exercise precise control over interfaces are constrained by a limited understanding of growth pathways and kinetics. Here we demonstrate that shuttered molecular beam epitaxy induces rearrangements of atomic planes at a polar / non-polar junction of LaFeO${}_3$ (LFO) / $n$-SrTiO${}_3$ (STO) depending on the substrate termination. Surface characterization confirms that substrates with two different (TiO${}_2$ and SrO) terminations were prepared prior to LFO deposition; however, local electron energy loss spectroscopy measurements of the final heterojunctions show a predominantly LaO / TiO${}_2$ interfacial junction in both cases. Ab initio simulations suggest that the interfaces can be stabilized by trapping extra oxygen (in LaO / TiO${}_2$) and forming oxygen vacancies (in FeO${}_2$ / SrO), which points to different growth kinetics in each case and may explain the apparent disappearance of the FeO${}_2$ / SrO interface. We conclude that judicious control of deposition timescales can be used to modify growth pathways, opening new avenues to control the structure and properties of interfacial systems.

arXiv comment21 pages, 7 figures

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Cited by in corpus (9)

• Probing Emergent Surface and Interfacial Properties in Complex Oxides via in situ X-ray Photoelectron Spectroscopy
• Nanoscale Oxygen Defect Gradients in the Actinide Oxides
• Thickness Dependent OER Electrocatalysis of Epitaxial LaFeO${}_3$ Thin Films
• Interface properties and built-in potential profile of a LaCrO${}_3$/SrTiO${}_3$ superlattice determined by standing-wave excited photoemission spectroscopy
• Correlating surface stoichiometry and termination in SrTiO${}_3$ films grown by hybrid molecular beam epitaxy
• Unexpected Termination Switching and Polarity Compensation in LaAlO3/SrTiO3 heterostructures
• Direct Observation and Control of Surface Termination in Perovskite Oxide Heterostructures
• Order-Disorder Behavior at Thin Film Oxide Interfaces
• Probing the polar-nonpolar oxide interfaces using resonant x-ray standing wave techniques