He constructed a camera and collected data but unfortunately his assistant made a calculation error and found the powder diffraction patterns did not fit the Braggs' values. The response given was ‘no, we have tried but haven’t succeeded’ and that became the challenge for Hull to find the crystal structure of iron. After a visit from Sir William Bragg to his laboratory talking about the X-ray crystal analysis work which he and his son were doing, Hull approached Bragg and asked if he had found the crystal structure of iron. Hull, who until 1916 had nothing in common with crystallography, became interested in the magnetic properties of some elements, particularly iron. Explanation of this pattern became the basis of the powder diffraction method we use today.Īcross the water, Albert W. The experiments were initially unsuccessful but this did not discourage Debye and Scherrer: they constructed a camera (now known as a Debye-Scherrer camera) which, when joined with a source of characteristic X-rays, produced a diffraction pattern with unexpectedly sharp lines. The first experiments on powders, or polycrystals, were by Paul Scherrer, a Swiss physicist, and were guided by Peter Debye's suggestion that "specific diffraction effects should be produced with X-rays by the regular spacing of electrons on circular orbits". Keene, but the meaning of the observed rings was not understood at that time. Some results of experiments performed on powders or samples having a polycrystalline component were published as early as 1913 by W. The route to the discovery of the powder diffraction (PD) method was not straightforward.
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