Centre for Research in NanoEngineering (CRnE-UPC)

摘要

Soon after the discovery of X-rays by Rontgen, in 1895, the idea that crystals could be used as a diffraction grating for X-rays was proposed by Ewald and von Laue, developed a law that connects the scattering angles and the size and orientation of the unit-cell spacings in the crystal. Just a few months later, in 1912, William Lawrence Bragg and his father presented the mathematical relationship which relates the periodicities in the crystal to the scattering observed. Although simple, Bragg's law confirmed the existence of real particles at the atomic scale, and provided a powerful new tool for studying crystals. These early developments, together with the construction of the first practical transmission electron microscope by Prebus and Hillier in 1938 (using concepts developed earlier by Knoll and Ruska in 1933) can be considered as the prehistory of characterization of matter at nanoscale, a discipline therefore close to its 100th birthday.