Abstract
The spinel/perovskite heterointerface γ−Al2O3/SrTiO3 hosts a two-dimensional electron system (2DES) with electron mobilities exceeding those in its all-perovskite counterpart LaAlO3/SrTiO3
by more than an order of magnitude, despite the abundance of oxygen
vacancies which act as electron donors as well as scattering sites. By
means of resonant soft x-ray photoemission spectroscopy and ab initio
calculations, we reveal the presence of a sharply localized type of
oxygen vacancies at the very interface due to the local breaking of the
perovskite symmetry. We explain the extraordinarily high mobilities by
reduced scattering resulting from the preferential formation of
interfacial oxygen vacancies and spatial separation of the resulting
2DES in deeper SrTiO3
layers. Our findings comply with transport studies and pave the way
towards defect engineering at interfaces of oxides with different
crystal structures.
Original language | English |
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Article number | 161409 |
Journal | Physical Review B |
Volume | 96 |
Issue number | 16 |
Number of pages | 6 |
ISSN | 2469-9950 |
DOIs | |
Publication status | Published - 2017 |