Electronic and Structural Transitions of LaAlO₃ /SrTiO₃ Heterostructure Driven by Polar Field-Assisted Oxygen Vacancy Formation at the Surface.

ABSTRACT: The origin of 2D electron gas (2DEG) at LaAlO₃ /SrTiO₃ (LAO/STO) interfaces has remained highly controversial since its discovery. Various models are proposed, which include electronic reconstruction via surface-to-interface charge transfer and defect-mediated doping involving cation intermixing or oxygen vacancy (V_O ) formation. It is shown that the polar field-assisted V_O formation at the LAO/STO surface plays critical roles in the 2DEG formation and concurrent structural transition. Comprehensive scanning transmission electron microscopy analyses, in conjunction with density functional theory calculations, demonstrate that V_O forming at the LAO/STO surface above the critical thickness (t_c ) cancels the polar field by dopi

SUBMITTER: Song K 

PROVIDER: S-EPMC8292910 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature