A termination-insensitive and robust electron gas at the heterointerface of two complex oxides.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31492862.
- Also identified by DOI 10.1038/s41467-019-12036-5 and PMC identifier 6731279.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The single-crystal SrTiO<sub>3</sub> (001) has two different surface terminations, TiO<sub>2</sub> and SrO. One most remarkable observation in previous studies is that only the heterointerfaces with TiO<sub>2</sub>-terminated SrTiO<sub>3</sub>, which usually combines with polar oxides such as LaAlO<sub>3</sub>, host an electron gas. Here we show that a robust electron gas can be generated between a non-polar oxide, CaHfO<sub>3</sub>, and SrTiO<sub>3</sub> (001) with either termination. Unlike the well-known electron gas of LaAlO<sub>3</sub>/SrTiO<sub>3</sub>, the present one of CaHfO<sub>3</sub>/SrTiO<sub>3</sub> essentially has no critical thickness of CaHfO<sub>3</sub>, can survive a long-time oxygen annealing at high temperature, and its transport properties are stable under exposure to water and other polar solvents. By electrostatic gating through CaHfO<sub>3</sub>, field-effect devices are demonstrated using CaHfO<sub>3</sub>/SrTiO<sub>3</sub> heterointerfaces with both terminations. These results show that the electron gas reported in the present study is unique and promising for applications in oxide electronics.