Neutron Sciences Directorate

Neutron reflectometry utilizes the refractive properties of thermal and cold neutrons (i.e., change in angle when light or other waves pass through a medium) to probe surface and interfacial structures of thin films on length scales of 0.5–350 nm. Due to the scattering properties of the neutron, reflectometry is particularly useful for studying magnetic and hydrogen-bearing materials. Roughness of surfaces should be <1 nm (rms) and thickness uniformity of films should be <5% averaged over micron lateral dimensions. Samples should be >1cm². Two reflectometry instruments are available to users at ORNL: Liquids Reflectometer (LIQREF) and Magnetism Reflectometer (MAGREF).