Journal Article

FZJ-2018-04658

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Charge-transfer in B-site-depleted NdGaO 3 /SrTiO 3 heterostructures

Gunkel, F. (Corresponding author)FZJ* ; Lenser, C.FZJ* ; Baeumer, C.FZJ* ; Borgatti, F. ; Offi, F. ; Panaccione, G. ; Dittmann, R.FZJ*

2018
AIP Publ. Melville, NY

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Please use a persistent id in citations: http://hdl.handle.net/2128/19717  doi:10.1063/1.5038773

Abstract: 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.

Keyword(s): Information and Communication (1st) ; Condensed Matter Physics (2nd) ; Materials Science (2nd)

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Contributing Institute(s):

1. Elektronische Materialien (PGI-7)
2. Werkstoffsynthese und Herstellungsverfahren (IEK-1)

Research Program(s):

1. 144 - Controlling Collective States (POF3-144) (POF3-144)
2. SOFC - Solid Oxide Fuel Cell (SOFC-20140602) (SOFC-20140602)

Appears in the scientific report 2018

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Database coverage:
; ; ; ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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