| 초록 |
Functional materials and devices supporting our life are constructed on the basis of electric and magnetic properties emerged from fundamental atomic arrangements. Thus high-resolution observation of electric and magnetic field is important to understand mechanism of its function. In this regard, electron holography in the transmission electron microscope (TEM) is a unique and powerful technique to quantitatively observe electric and magnetic potential distributions, and has been widely used for functional materials. Here I show direct imaging and quantitative analysis of the two-dimensional electron liquid (2DEL) forming at the LaAlO3/SrTiO3 interface by using inline electron holography. The 2DEL is formed by the occupied 3d-orbitals of cations within only a few nanometers of the interface and often involves an interplay of electronic states with distinct orbital character and symmetry, which affect electronic mobility, superconductivity, Rashba spin-orbit coupling, and magnetism. In this presentation, I will also introduce other advanced TEM techniques (i.e. differential phase contrast (DPC) imaging in scanning TEM (STEM), Lorentz TEM) for the direct observation of electric and magnetic field in materials. |
