The technique provides valuable information over a wide variety of scientific and technological applications including chemical aggregation, polymer and surfactant adsorption, structure of thin film magnetic systems, biological membranes, etc.
It has become a technique widespread at reactor and spallation sources, with a wide range of available fitting software and standardised data formats.
The exact shape of the reflectivity profile provides detailed information about the structure of the surface, including the thickness, density, and roughness of any thin films layered on the substrate.
A typical neutron reflectometry plot displays the reflected intensity (relative to the incident beam) as a function of the scattering vector: where
While some quantities such as the SLD and the thickness of thin films can be estimated from the total reflection edge and the angular / q width of.
interference fringes, in general fitting software is needed to extract the full information including roughnesses or multiple thicknesses from a neutron reflectivity curve.
Dual polarisation interferometry is one optical method which provides analogous results to neutron reflectometry at comparable resolution although the underpinning mathematical model is somewhat simpler, i.e. it can only derive a thickness (or birefringence) for a uniform layer density.
Disadvantages of neutron reflectometry include the higher cost of the required infrastructure, the fact that some materials may become radioactive upon exposure to the beam, and insensitivity to the chemical state of constituent atoms.
Moreover, the relatively lower flux and higher background of the technique (when compared to x-ray reflectivity) limit the maximum value of