André Authier
- Published in print:
- 2013
- Published Online:
- September 2013
- ISBN:
- 9780199659845
- eISBN:
- 9780191748219
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199659845.003.0008
- Subject:
- Physics, Crystallography: Physics
This chapter recalls the early developments of X-ray crystallography and how it spread throughout the world, and the first theoretical and experimental investigations that led to the determination of ...
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This chapter recalls the early developments of X-ray crystallography and how it spread throughout the world, and the first theoretical and experimental investigations that led to the determination of crystal structures, from the simpler trial-and-error methods to the systematic use of space groups and the introduction of Fourier syntheses. The Lorentz and polarization factors and the atomic scattering factor were analysed. W. H. Bragg introduced the concept of integrated intensities, and W. L. Bragg that of absolute intensities. Expressions for the diffracted intensity by small and large perfect crystals were obtained by C. G. Darwin, who also introduced the notion of mosaic crystal to account for the observed diffracted intensities. It is shown how W. L. Bragg determined the structure of the trigonal carbonates from the simple observation of diffracted intensities by various reflecting planes. The discovery of powder diffraction by Debye and Sherrer in Germany and by Hull in the United States is recounted. The first applications of the rotating crystal method to crystal structure determinations are described. Finally, the determination of three landmark crystal structures is explained: hexamethylene tetramine, graphite, and the benzene ring.Less
This chapter recalls the early developments of X-ray crystallography and how it spread throughout the world, and the first theoretical and experimental investigations that led to the determination of crystal structures, from the simpler trial-and-error methods to the systematic use of space groups and the introduction of Fourier syntheses. The Lorentz and polarization factors and the atomic scattering factor were analysed. W. H. Bragg introduced the concept of integrated intensities, and W. L. Bragg that of absolute intensities. Expressions for the diffracted intensity by small and large perfect crystals were obtained by C. G. Darwin, who also introduced the notion of mosaic crystal to account for the observed diffracted intensities. It is shown how W. L. Bragg determined the structure of the trigonal carbonates from the simple observation of diffracted intensities by various reflecting planes. The discovery of powder diffraction by Debye and Sherrer in Germany and by Hull in the United States is recounted. The first applications of the rotating crystal method to crystal structure determinations are described. Finally, the determination of three landmark crystal structures is explained: hexamethylene tetramine, graphite, and the benzene ring.
