A ROAD MAP FOR QUANTITATIVE HREM

摘要

The improvement in the resolution of electron microscopes to below 1 Angstrom has not to be regarded as a gradual improvement in the performance but more as a quantum leap. Indeed it now becomes possible to visualize individual atoms, the alphabet of nature. In X-ray terminology, electron microscopy is now able to resolve atomic structures. Since also the whole image formation process including the interaction of the electron with the object is now theoretically well understood it will also become possible to quantitatively refine the atomic structures with a precision that is comparable to that of X-ray diffraction. However thus far these potentialities are not yet met. We will discuss the state of the art.