Introduction to Polarized Neutron Reflectivity | NNSS 2025

Introduction to Polarized Neutron Reflectivity Presented by Timothy Charlton 1st National Neutron Scattering School, 2025 Oak Ridge National Laboratory (ORNL) In this lecture, Timothy Charlton introduces the principles and applications of polarized neutron reflectivity as a technique for probing the structure and magnetism of thin films and layered materials. The presentation explains how neutron reflectivity provides depth-resolved information at interfaces, and how polarization analysis enables separation of nuclear and magnetic scattering contributions. Charlton outlines the theoretical foundations of neutron reflectivity, including wave interference at interfaces, scattering length density profiles, and the role of neutron spin in magnetic contrast. The lecture discusses practical aspects of instrument design and data interpretation, drawing on experience from reflectometer development at large-scale neutron facilities and the integration of polarized beam capabilities. By combining structural sensitivity with magnetic specificity, polarized neutron reflectivity offers a powerful tool for studying multilayer systems, thin film magnetism, and interfacial phenomena. The session emphasizes how careful experimental design and modeling allow researchers to extract quantitative depth profiles of both chemical and magnetic structure in complex materials systems. Learn more about neutron science at ORNL: https://neutrons.ornl.gov Learn about the National Neutron Scattering School at ORNL: https://neutrons.ornl.gov/nns