The field of ultra-thin films, a subgroup of nanomaterials, has seen an upsurge in research within the last 30 years. Studies have primarily been done using neutron and x-ray reflectometry. The technique of polarized neutron reflectometry or PNR is a unique non-destructive tool to understand thin film magnetism in mesoscopic length scale.This book presents x-ray and neutron reflectometry techniques and how they can be used to explore interface structure and magnetism at mesoscopic ...