André GUINIER (1911-2000)

He was a member of the Academy of Sciences, Emeritus Professor of Paris-Sud University, first Director of Orsay solid-state physics Laboratory, and president of the SFMC in 1960.

André Guinier passed away at the age of 89. He was one of the greatest figures of crystallography at the end of 20th century.

He was born in Nancy, where his father was a member of the Academy of Sciences in the rural economy section, and Director of the Forestry School. He was a brilliant pupil and entered the Ecole Normale Supérieure in 1930, where he chose to study physics, with illustrious professors such as G. Bruhat, H. Abraham and E. Bloch. Charles Manguin, who was a Sorbonne teacher. The latter gave him a taste for crystallography.André Guinier’sfirst works were devoted to the design and production of a x-ray diffraction chamber, using a monochromator with a geometry leading to a perfect beam focusing. This chamber, commonly called “Guinier’s chamber”, allowed for remarkable progress in radiocrystallography.

In particular, thanks to this chamber it became possible to study x-ray scattering near an incident beam. André Guinier was the pioneer of the observation of this “scattering to little angles”, which led him to a quantitative study of numerous crystal defect categories. Everybody knows the “Guinier-Preston zones”, areas of atomic concentration in an alloy (the first example was Al-Cu).

André Guinier demonstrated the function of these “G-P zones” in the structural hardening phenomenon, so important in metallurgy. The scattering towards little angles led André Guinier to define a “rotation radius” for the aggregates of any kind which could thus be studied. Crystal defects are sometimes due to radiation effects. It has led André Guinier and his students to remarkable breakthroughs. One of André Guinier’s greatest merits was that he had always surrounded himself with first rate collaborators; he had also always given the original impulse to numerous talented researchers. One of the most brilliant was Raymond Castaing. The notion of “Castain’s microprobe” comes from Guinier’s laboratory, and the first publication announcing this probe (1948) is co-signed by Guinier and Castaing.
In parallel to his research works, André Guinier had the very great merit of writing landmark books and treaties on crystallography teaching. His work on “radio crystallography theory and technique”, first published in 1956, reissued and translated into four languages, was the bible for crystallographers.

André Guinier had also known how to assume various organisational responsibilities with elegance and efficiency. He was president of the SFMC, president of the Physics French Society, president of the Crystallography International Union. The Academy of Sciences paid much attention to this very active member. When the Orsay Sciences University was created, he accepted to become its president. He was one of the founding members of Orsay’s Solid-State Physics Laboratory. Thanks to André Guinier and Jacques Friedel, this laboratory was involved in the most significant advances of this so fruitful scientific discipline.

A learned, a discoverer, a maker and also a friend has left us. He was, for all the people who had the privilege of encountering him, a stimulating and friendly illustrious professor.

Hubert Curien