Divergent-beam X-ray photography of crystals
- 27 March 1947
- journal article
- Published by The Royal Society in Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
- Vol. 240 (817), 219-250
- https://doi.org/10.1098/rsta.1947.0002
Abstract
Divergent-beam X-ray photography of single crystals by transmission can be used to study the ‘extinction’, that is, the diminution of the transmitted radiation that takes place at the Bragg reflexion angles. The intensity and geometry of the absorption lines observed give useful information about the texture of the crystal. Divergent beam photographs have shown that many crystals of organic compounds are unexpectedly perfect, and that sudden cooling to liquid-air temperatures will increase the mosaic character of their structure by an important factor and make them more suitable for structural analysis by the usual methods. Type I diamonds, and natural ice even near to its melting-point, are also found to possess a high degree of perfection, which cannot be removed by liquid-air treatment. The divergent beam method may be used for the determination of orientation, but it is important that the wave-length of X-rays employed should be correctly related to the size and nature of the crystal. In certain favourable cases it is possible to make precision measurements of lattice constant or of wave-length from divergent beam photographs, without the use of any kind of precision apparatus. By such means it has been shown that the C—C distance in individual diamonds varies from 1541.53(± 0-02) to 1541.27X, (1.54465-1-54440A), a difference presumably due to varying impurity content. Using diamond and a brass anticathode, the Zn Ka 1 wave-length, relative to Cu K Ka 1 as 1537.40X, is found to be 1432.21 ( ± 0-04) X. Temperature control would improve the accuracy of this measurement, which is, however, in good agreement with the latest value obtained by orthodox precision methods.Keywords
This publication has 12 references indexed in Scilit:
- Präzisionsmessung von Gitterkonstanten mit einer Kompensationsmethode. IIAnnalen der Physik, 1941
- Präzisionsmessung von Gitterkonstanten mit der KompensationsmethodeThe Science of Nature, 1937
- Über die Interferenzen aus Gitterquellen bei Anregung durch RöntgenstrahlenAnnalen der Physik, 1936
- Röntgenlichtquelle im EinkristallThe Science of Nature, 1935
- Shapes and Wavelengths ofSeries Lines of Elements Ti 22 to Ge 32Physical Review B, 1935
- The Intensity of Reflection of X-Rays from DiamondPhysical Review B, 1929
- LXXXI.The intensity of reflexion of X-rays by crystalsJournal of Computers in Education, 1926
- XXIX. The intensity of reflexion of X-rays by rock-saltJournal of Computers in Education, 1921
- LXXVIII. The theory of X-ray reflexion. Part IIJournal of Computers in Education, 1914
- An X-Ray Absorption BandNature, 1914