http://hdl.handle.net/20.500.12128/8371
Title: | In-situ four-tip STM investigation of the transition from 2D to 3D charge transport in SrTiO3 |
Authors: | Leis, Arthur Rodenbücher, Christian Szot, Krzysztof Cherepanov, Vasily Tautz, F. Stefan Voigtländer, Bert |
Keywords: | SrTiO3; In-situ |
Issue Date: | 2019 |
Citation: | Scientific Reports, Vol. 9 (2019), Art. No. 2476 |
Abstract: | The electrical properties of SrTiO3(100) single crystals were investigated in-situ at different stages of thermal reduction by means of a 4-tip STM. Using the tips of the STM as electrical probes, distancedependent four-point measurements were performed at the surface of the crystal at room temperature after reduction by thermal treatment. For annealing temperatures T ≤ 700 °C, charge transport is confined to a surface region <3 μm below the surface. For reduction at T ≥ 900 °C a transition from a conducting 2D sheet with insulating bulk to a system with dominant 3D bulk conductivity is found. At an intermediate reduction temperature of T = 800 °C, a regime with mixed 2D/3D contributions is observed in the distance-dependent resistance measurements. Describing the depth-dependent conductivity with an analytical N-layer model, this regime of mixed 2D/3D conductivity is evaluated quantitatively under the assumption of an exponentially decaying conductivity profile, correlated with the previously observed depth-dependent dislocation density in the sample. A non-monotonous temperature dependence of the 3D conductivity in the respective conducting layer is found and possible underlying mechanisms are discussed, particularly with regard to non-intrinsic material properties depending on details of the sample preparation. |
URI: | http://hdl.handle.net/20.500.12128/8371 |
DOI: | 10.1038/s41598-019-38888-x |
ISSN: | 2045-2322 |
Appears in Collections: | Artykuły (WNŚiT) |
File | Description | Size | Format | |
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Leis_In-situ_four-tip_STM_investigation.pdf | 1,57 MB | Adobe PDF | View/Open |
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