Bestimmung Der GrößE Und Der Inneren Struktur Von Kolloidteilchen Mittels RöNtgenstrahlen. Vorgelegt Von P.Debye In Der Sitzug Vom 26. Juli 1918. Scherrer, Paul Physik

Nachr. Ges. Wiss. Gött. 1918. - Göttingen 1918, 8°, 3 pp., orig. Broschur. Rare Offprint! The Scherrer equation, in X-ray diffraction and crystallography, is a formula that relates the size of sub-micrometre crystallites in a solid to the broadening of a peak in a diffraction pattern. It is often referred to, incorrectly, as a formula for particle size measurement or analysis. It is named after Paul Scherrer. It is used in the determination of size of crystals in the form of powder. Paul Hermann Scherrer (1890-1969) was a Swiss physicist. In 1908, he enrolled at Swiss Federal Polytechnic (later known as ETH Zurich), changing course from Botany to Mathematics and Physics after two semesters. In 1912, Scherrer spent one semester at Königsberg University, then undertook further studies at the University of Göttingen, graduating from there with a doctorate on the Faraday effect in the hydrogen molecule. In 1916, while still working on his dissertation, he and his tutor, Peter Debye, developed the "Debye-Scherrer powder method", a procedure using X-rays for the structural analysis of crystals. This made an important contribution to the development of the scattering techniques that are still used in the large facilities at the Paul Scherrer Institute to this day. Debye received the Nobel Prize in Chemistry for this work in 1936. He is perhaps best known for determining the inverse relationship between the width of an x-ray diffraction peak and the crystallite size. This work was published in 1918.