Offcut Substrate-Induced Defect Trapping at Step Edges.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38668651.
- Also identified by DOI 10.1021/acs.nanolett.4c00832 and PMC identifier 11082922.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
We report step edge-induced localized defects suppressing subsequent antiphase boundary formation in the bulk structure of a trilayer oxide heterostructure. The heterostructure encompasses a layer of La<sub>0.66</sub>Sr<sub>0.34</sub>MnO<sub>3</sub> sandwiched between a superconducting La<sub>1.84</sub>Sr<sub>0.16</sub>CuO<sub>4</sub> bottom layer and an insulating La<sub>2</sub>CuO<sub>4</sub> top layer. The combination of a minor <i>a</i>-axis mismatch (0.11 Å) and a pronounced <i>c</i>-axis mismatch (2.73 Å) at the step edges leads to the emergence of localized defects exclusively forming at the step edge. Employing atomically resolved electron energy-loss spectroscopy maps, we discern the electronic state of those structures in the second La<sub>0.66</sub>Sr<sub>0.34</sub>MnO<sub>3</sub> unit cell near the step edge. In particular, a reduction in the pre-edge region of the O-<i>K</i> edge indicates the formation of oxygen vacancies induced by the strained step edge. This study underscores our capability to control defects at the nanoscale.