Page 55 - Neutrons for Sciences and Society

Chapter 2: Portrait of three founders of the ILL
for the existence of these compounds, but soon it was found that manganese oxide, MnO had a magnetic susceptibility which varied with temperature following that predicted by Néel for antiferromagnetism. It was necessary to wait until 1949 for Shull to demonstrate the accuracy of Néel’s predictions with the help of neutron diffraction. This was sufficent to induce in Néel a great interest in neutrons, and hence for the reactors which produce them.
During the war he worked on magnetic mines at the research centre of the French navy. He had the idea to demagnetise boats. This was a very demanding operation which required capabilities from Néel well beyond those of a researcher. From this period
on he would always keep a high regard for sailors, and a taste for industrial work.
When the university of Strasbourg withdrew to Clermont Ferrand, he chose to settle in Grenoble following the suggestion of Félix Esclangon, director of the “Institut polytechnique de Grenoble” (IPG). There is the following description of Grenoble before the war in an interview given by Jean Wyart45:
“Grenoble where the university was brand new, but where nothing was done. Very expensive apparatus was left in corridors for two years without even being unpacked”.
Such was the state of research in Grenoble before the arrival of Néel. He created and named his own Ferromagnetism Laboratory, which became the Laboratory of Electrostatics and Physics of Metals (LEPM). This was the first laboratory belonging to the
45 Cahiers pour l’histoire du CNRS, (1989), 2, p13-34. 46