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NIST Center for Neutron Research

Reflectometry

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Schematic of neutron reflectivity (plane-waves)
Neutron reflectivity is defined in terms of the incoming momentum vector kz,i and outgoing vector kz,f; for flat interfaces the only possible momentum transfer is perpendicular to the surface, and the measured reflectivity as a function of Q = kz,f - kz,i is a measure of the scattering potential as a function of depth into the film structure.
Credit: Brian Kirby

Reflectometry uses neutrons scattered at grazing angles to probe the nuclear and magnetic composition of flat samples. Common types of materials studied include biological membranes, magnetic multilayers, and polymer films. The NCNR currently operates three reflectometers - PBR, MAGIK, and NG-7 - each specially configured for different types of research. Additionally, construction is underway on CANDOR, a revolutionary new white beam reflectometer. Please visit the instrument pages (linked at right) for specific information.

This is a typical result from measuring a single-layer thin-film sample with reflectometry; a clear set of interference fringes is visible, and gives information about the thickness, density and roughness of the layer. 
This is a typical result from measuring a single-layer thin-film sample with reflectometry; a clear set of interference fringes is visible, and gives information about the thickness, density and roughness of the layer. 
Credit: Brian Kirby

Data Analysis

Reference Material

Interactive online scattering demos

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polarized reflectivity calculator
Polarized reflectivity calculator		 Practice aligning
Instrument simulator		 Off-specular planner
Offspecular scattering planner
Neutron research

Contacts

Created April 17, 2017, Updated May 5, 2021