TABLE OF CONTENTS L.Pusztai
Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, Budapest, P.O. Box 49, H-1525, Hungary
This chapter reviews the most important neutron scattering methods that provide valuable information for a chemist. Particular emphasis is placed on the microscopic structure and dynamics in the liquid state.
Before going into details of the scattering of neutrons in condensed phases, some basic properties of this elementary particle should be recalled, as these characteristics play a central role in the scattering process.
The neutron is a particle of mass 1.675 10 ? 27 kg, magnetic moment of ?1.913 ? N ( ?N being the nuclear magneton, 5.501 10 ? 27 J/T) and possessing no electric charge. These properties (particularly the electric neutrality) make the neutron one of the most suitable probe for atomic scale structure and dynamics: neutrons can penetrate deep into the bulk of condensed phases without destroying chemical bonds. Since neutrons do not interact with the electrons via Coulomb forces, they are scattered by the nuclei.
The wavelength of thermal (and cold ) neutrons from reactor or accelerator sources varies between about 0.1 and 20 (1 =0.1 nm=10 ? 10 m) which corresponds to atomic scale distances. As it will be shown later, for the study of the structure of condensed phases it is the interference of the scattered radiation that is most important: interference effects, in turn, are...
