Atomic and electronic structures of SrTiO3/GaAs heterointerfaces: An 80-kV atomic-resolution electron energy-loss spectroscopy study

Article

关键词: LAYER-DEPOSITION;    THIN-FILMS;    OXIDE;    AL2O3;    FERROELECTRICITY;    GAAS(001);    TI/GAAS;    GROWTH;   

DOI  :  10.1103/PhysRevB.85.165406

来源: SCIE

【 摘 要 】

We have examined the atomic and electronic structures of epitaxially grown, ultrathin SrTiO3 (100) films on GaAs (001) using 80-kV aberration-corrected atomic-resolution Z-contrast imaging and electron energy-loss spectroscopy (EELS) to develop a fundamental understanding of the interfacial structure-property relationships. We find that the interface is atomically abrupt and no surface reconstruction of the GaAs (001) surface is observed. Using atomic-column resolved EELS, we examine the oxygen vacancy and Ti concentrations in the SrTiO3 film and across the heterointerface. We show that Ti diffuses into the first few monolayers of GaAs. Using a combination of EELS and first-principles calculations, we present evidence for the formation of As oxides at the interface depending on the thin-film growth conditions. These findings are used to explain the differences in the transport behavior of the films.

【 授权许可】

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