| Autor: |
F. Gunkel, C. Lenser, C. Baeumer, F. Borgatti, F. Offi, G. Panaccione, R. Dittmann |
| Jazyk: |
angličtina |
| Rok vydání: |
2018 |
| Předmět: |
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| Zdroj: |
APL Materials, Vol 6, Iss 7, Pp 076104-076104-9 (2018) |
| Druh dokumentu: |
article |
| ISSN: |
2166-532X |
| DOI: |
10.1063/1.5038773 |
| Popis: |
Cation stoichiometry has been identified as a major key in establishing 2-dimensional electron gases (2DEGs) in oxide heterostructures. Here, we discuss a 2DEG formation scenario in B-site deficient perovskite/perovskite heterostructures, which previously were predicted to show insulating behavior. We elaborate an ionic picture based on oxygen-vacancy-buffered B-site vacancy defects in the polar oxide layer that yields a continuous transition from 2DEG formation to less conducting interfaces to insulating interfaces with increasing B-site deficiency. Experimentally, a corresponding modulation of charge transfer across NdGaO3/SrTiO3 interfaces is inferred using hard x-ray photoelectron spectroscopy analysis and transport experiments. With increasing B-site deficiency, we observe a decrease of the interfacial Ti3+ core level contribution, indicating a reduced charge transfer at the interface. This result is corroborated by temperature-dependent transport measurements, revealing increased low temperature resistance, with a dominant influence of a reduced electron density in the Ga-depleted sample. We consider a redistribution of oxygen vacancies in the B-site deficient polar oxide layer to explain the alleviated interface reconstruction, adding a new perspective on potential built-up in polar-oxide thin films. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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