The 'Disrotation': a New Line Defect in Complex Oxide NdTiO3

Abstract:

Complex oxides with perovskite structure exhibit abundant electronic, spin, and structural phenomena including superconductivity, multiferroic behaviors, and Mott-Hubbard metal-insulator transition characteristics. The extreme sensitivity of these phenomena to crystal structure, bond length, bond angle, doping, and strain makes this material class very interesting for both fundamental physics and new technological applications. In this study, we investigate interfaces and defects in NdTiO₃/SrTiO₃ heterostructures using analytical scanning transmission electron microscopy and first-principles calculations. It is found that the strain in the NdTiO₃ film supplies driving force to form a new type of line defect to adapt the strain. To the best of our knowledge this new type of defect has yet become known. Here, we report the discovery of this new type of line defect in strained NdTiO₃/SrTiO₃ heterostructure and present its atomic and electronic structure using analytical STEM with the assistant of density functional theory (DFT) calculations.