摘要:
A scanning tunneling atom-probe microscope and method for identifying atoms at an identified site on a sample surface involves first identifying the atoms of interest on the sample surface in images formed by a conventional scanning tunneling microscope. These atoms are then transferred to the tip of the scanning tunneling microscope. The sample is then removed, and the atoms ejected from the tip into a conventional time-of-flight spectrometer. By measuring the time of flight of the atoms from the tip to a channel-plate ion detector, the atomic number of the atoms may be determined.
摘要:
A nozzle for producing a single-file stream of droplets of a fluid, methods using the nozzle, and an injector, comprising the nozzle of the invention, for providing the single-file stream of droplets of a fluid to a high-vacuum system are described. The nozzle comprises two concentric tubes wherein the outer tube comprises a smoothly converging-diverging exit channel and the outlet end of the first tube is positioned within the converging section of the exit channel.
摘要:
In electron microscopy, resolution is improved by using an atom or atom-array focuser, with the atom or atom array serving as an electrostatic lens at a focal plane of an electron beam probe having a beam size less than about 0.2 nm at the focal plane. An electrostatic lens can be included in ultra-high resolution microscopes wherein (i) in a linear atom array, the atoms are in alignment with the electron path, (ii) the distance between a sample and the electrostatic lens is adjustable, (iii) a two-dimensional focuser is used, (iv) a sample is at Fourier image distance from a two-dimensionally periodic focuser, (v) a two-dimensional detector or detector array is used, and/or (vi) the electron beam is scanned at the focal plane.