Interface dipole between two metallic oxides caused by localized oxygen vacancies

Albina Y. Borisevich,
Andrew R. Lupini,
Jun He,
Anna N. Morozovska,
George S. Svechnikov,
Pu Yu,
Ying-Hao Chu,
Ramamoorthy Ramesh,
Sokrates T. Pantelides,
Sergei V. Kalinin,
Stephen J. Pennycook

Інститут проблем матеріалознавства ім. І. М. Францевича НАН України , вул. Кржижановського 3, Київ, 03142, Україна
Physical Review B - Меріленд, США: Американське Фізичне Суспільство (APS), 2012, #86


Oxygen vacancies are increasingly recognized to play a role in phenomena observed at transition-metal oxide interfaces. Here, we report a study of SrRuO3 and La0.7Sr0.3MnO3 interfaces using a combination of quantitative aberration-corrected scanning transmission electron microscopy, electron energy-loss spectroscopy, and density functional calculations. Cation displacements are observed at the interface, indicative of a dipolelike electric field even though both materials are nominally metallic. The observed displacements are reproduced by theory if O vacancies are present in the near-interface La0.7Sr0.3MnO3 layers. The results suggest that atomic-scale structural mapping can serve as a quantitative indicator of the presence of O vacancies at interfaces.