Neutron reflectivity at the ILL

R.Cubitt, G. Fragneto and A. Wildes

Institut Laue-Langevin, Grenoble, France

Neutron reflectometry is an experimental technique for examining surfaces and buried interfaces. It gives sensitive information on the atomic composition and magnetic properties of a material as a function of depth with Angstrom resolution, and can probe in-plane structures with length scales of the order of micrometers. Neutrons have a high probability of interaction with light elements such as hydrogen and carbon, with magnetic moments, and the probability varies with isotope rather than with element. Unprecedented and unique information can be obtained by exploiting these properties through techniques such as contrast variation, where isotope substitution can be used to highlight or suppress scattering, and polarization analysis, where vector magnetization density can be probed by measuring the change in direction of a neutron's spin. Neutron reflectometry is thus being used in an increasing number of scientific fields from biology to physics.

There are two neutron reflectometers at the ILL that may be used by researchers: D17 is an ILL-owned instrument, and ADAM is run by a German consortium in cooperation with the ILL. Neutron reflectometry will be briefly explained, and various examples from recent experiments will be used to illustrate the capabilities of the techniques. The presentation will end with an open invitation to come and use the instrument.