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Title: nomalous Interface and Surface Strontium Segregation in (La 1-ySr y) 2CoO 4 /La 1-xSr xCoO 3- Heterostructured Thin Films

Heterostructured materials have shown unusual physiochemical properties at the interfaces such as two dimensional electron gas systems, high-temperature superconductivity, and enhanced catalysis. Here we report the first atomic-scale evidence of the microscopic structure of a perovskite/Ruddlesden-Popper heterostructure (having La1-xSrxCoO3- /(La1-ySry)2CoO4 ), and anomalous strontium segregation at the interface and in the Ruddlesden-Popper structure using direct X-ray methods combined with ab initio calculations. The remarkably enhanced activity of such heterostructured surfaces relative to bulk perovskite and Ruddlesden-Popper oxides previously shown for oxygen electrocatalysis at elevated temperatures can be attributed to reduced thermodynamic penalty of oxygen vacancies in the oxide structure associated with Sr segregation observed in the heterostructure. Our findings provide insights for the design of highly active catalysts for energy conversion and storage applications.
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  1. Massachusetts Institute of Technology (MIT)
  2. Harvard University
  3. Argonne National Laboratory (ANL)
  4. ORNL
  5. University of Washington
  6. University of Wisconsin, Madison
Publication Date:
OSTI Identifier:
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry Letters; Journal Volume: 5; Journal Issue: 6
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States