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arXiv · 1804.04415

Point defects at cleaved Sr$_{n+1}$Ru$_n$O$_{3n+1}$(001) surfaces

Bernhard Stöger·Marcel Hieckel·Florian Mittendorfer·Zhiming Wang·Michael Schmid·Gareth S. Parkinson·David Fobes·Jin Peng·John. E. Ortmann·Andreas Limbeck·Zhiqiang Mao·Josef Redinger·Ulrike Diebold
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Abstract

The (001) surfaces of cleaved Sr$_3$Ru$_2$O$_7$ and Sr$_2$RuO$_4$ samples were investigated using low-temperature scanning tunneling microscopy and density functional theory calculations. Intrinsic defects are not created during cleaving. This experimental observation is consistent with calculations, where the formation energy for a Sr and O vacancy, 4.19 eV and 3.81 eV, respectively, is significantly larger than that required to cleave the crystal, 1.11 eV/(1 $\times$ 1) unit cell. Surface oxygen vacancies can be created through electron bombardment, however, and their appearance is shown to vary strongly with the imaging conditions. Point defects observed on as-cleaved surfaces result from bulk impurities and adsorption from the residual gas.

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Bernhard Stöger, Marcel Hieckel, Florian Mittendorfer, Zhiming Wang, Michael Schmid, Gareth S. Parkinson, David Fobes, Jin Peng, John. E. Ortmann, Andreas Limbeck, Zhiqiang Mao, Josef Redinger, Ulrike Diebold. 2018-04-12. Point defects at cleaved Sr$_{n+1}$Ru$_n$O$_{3n+1}$(001) surfaces. https://doi.org/10.1103/physrevb.90.165438

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