| 摘要 |
PROBLEM TO BE SOLVED: To provide a novel method for phase contrast image formation in a transmission electron microscopy.SOLUTION: In the method, an imaging electron beam itself is used to adjust a hole-free thin film for use as an actual phase plate, in some cases eliminating the need for ex-situ fabrication of a hole and reducing requirements for the precision of ZPP hardware. The electron optical properties of the ZPP hardware are modified primarily in two ways: by boring a hole using the electron beam; and/or by modifying the electro-optical properties by charging induced by the primary beam. Furthermore a method where a sample is focused by a lens downstream from the ZPP hardware is disclosed. A method for transferring a back focal plane of an objective lens to the aperture plane of a selected area and an optional plane conjugated with the back focal plane of the objective lens is also provided. |
