Christian Janot – författare

In 1984 physicists discovered a monster in the world of crystallography, a structure that appeared to contain five-fold symmetry axes, which cannot exist in strictly periodic structures. Such quasi-periodic structures became known as quasicrystals. A previously formulated theory in terms of higher dimensional space groups was applied to them and new alloy phases were prepared which exhibited the properties expected from this model more closely. Thus many of the early controversies were dissolved. In 2011, the Nobel Prize for Chemistry was awarded to Dan Shechtman for the discovery of quasicrystals. This primer provides a descriptive approach to the subject for those coming to it for the first time. The various practical, experimental, and theoretical topics are dealt with in an accessible style. The book is completed by problem sets and there is a computer program that generates a Penrose lattice.

In 1984 physicists discovered a monster in the world of crystallography, a structure that appeared to contain five-fold symmetry axes, which cannot exist in strictly periodic structures. Such quasi-periodic structures became known as quasicrystals. A previously formulated theory in terms of higher dimensional space groups was applied to them and new alloy phases were prepared which exhibited the properties expected from this model more closely. Thus many of the early controversies were dissolved. In 2011, the Nobel Prize for Chemistry was awarded to Dan Shechtman for the discovery of quasicrystals. This primer provides a descriptive approach to the subject for those coming to it for the first time. The various practical, experimental, and theoretical topics are dealt with in an accessible style. The book is completed by problem sets and there is a computer program that generates a Penrose lattice.

Comment invente-t-on des matériaux ? Existe-t-il des règles permettant de maîtriser leurs propriétés en fonction des besoins ? Quelle utilisation leur a-t-on réservée dans la vie quotidienne ? Les matériaux " intelligents " sont-ils pour demain ? À travers notamment l''exemple des quasicristaux, dont la découverte a révolutionné la compréhension que nous avions de la matière ordonnée, c''est toute l''épopée des hommes et des matériaux qui est ici retracée, depuis la préhistoire jusqu''à nos jours. Michel Duneau est directeur de recherche au CNRS, membre du Centre physique théorique de l''École polytechnique. Christian Janot est physicien à l''Institut Laue-Langevin et professeur à l''université Joseph-Fourier de Grenoble. Leurs travaux décisifs sur les quasicristaux sont reconnus dans le monde entier.

The Institut Max-von-Laue-Paul Langevin (ILL) in Grenoble regularly organ­ ises workshops that deal with the various applications of neutrons in physics, chemistry, biology and also in nuclear physics. The workshop" Atomic Trans­ port and Defects in Metals by Neutron Scattering", jointly organised by the Institut Laue-Langevin and the Institut fiir Festkorperforschung of the KFA­ Jiilich, was held in October 1985 in Jiilich. The study of problems in metal physics and in physical metallurgy is a traditional field of neutron scattering. The most commonly used methods are diffuse elastic, small-angle and inelastic scattering of neutrons. A number of problems can be identified where neutrons yield information that is supple­ mentary to that from other methods such as x-ray diffraction, synchrotron radiation or electron microscopy. In certain fields, for example spectroscopy for the investigation of atomic motions or for the investigation of magnetic properties, neutron scattering is a unique method. The facilities at the High Flux Reactor of the ILL, and also at the Jiilich and at other medium flux research reactors, have contributed numerous re­ sults in these fields. It was the aim of this workshop to give a survey of the present state of neutron scattering in metal physics.