This title appears in the Scientific Report :
2017
Please use the identifier:
http://dx.doi.org/10.1021/acsami.6b12706 in citations.
Thermodynamic Ground States of Complex Oxide Heterointerfaces
Thermodynamic Ground States of Complex Oxide Heterointerfaces
The formation mechanism of 2-dimensional electron gases (2DEGs) at heterointerfaces between nominally insulating oxides is addressed with a thermodynamical approach. We provide a comprehensive analysis of the thermodynamic ground states of various 2DEG systems directly probed in high temperature equ...
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Personal Name(s): | Gunkel, F. (Corresponding author) |
---|---|
Hoffmann-Eifert, S. / Heinen, R. A. / Christensen, D. V. / Chen, Y. Z. / Pryds, N. / Waser, R. / Dittmann, R. | |
Contributing Institute: |
Elektronische Materialien; PGI-7 |
Published in: | ACS applied materials & interfaces, 9 (2017) 1, S. 1086 - 1092 |
Imprint: |
Washington, DC
Soc.
2017
|
DOI: |
10.1021/acsami.6b12706 |
Document Type: |
Journal Article |
Research Program: |
Controlling Electron Charge-Based Phenomena |
Publikationsportal JuSER |
The formation mechanism of 2-dimensional electron gases (2DEGs) at heterointerfaces between nominally insulating oxides is addressed with a thermodynamical approach. We provide a comprehensive analysis of the thermodynamic ground states of various 2DEG systems directly probed in high temperature equilibrium conductivity measurements. We unambiguously identify two distinct classes of oxide heterostructures: For epitaxial perovskite/perovskite heterointerfaces (LaAlO3/SrTiO3, NdGaO3/SrTiO3, and (La,Sr)(Al,Ta)O3/SrTiO3), we find the 2DEG formation being based on charge transfer into the interface, stabilized by the electric field in the space charge region. In contrast, for amorphous LaAlO3/SrTiO3 and epitaxial γ-Al2O3/SrTiO3 heterostructures, the 2DEG formation mainly relies on the formation and accumulation of oxygen vacancies. This class of 2DEG structures exhibits an unstable interface reconstruction associated with a quenched nonequilibrium state. |