The National Institute of Standards and Technology (NIST) has developed a powerful technique called polarized neutron reflectometry (PNR) to study magnetic thin film materials. PNR allows researchers to measure the chemical composition and in-plane magnetization of materials with sub-nanometer resolution, making it ideal for studying buried interfacial magnetism and magnetic coupling in thin films.
Recent studies using PNR have revealed novel antiferromagnetic coupling between magnetic insulators and metals in heterostructures. For example, researchers discovered that when yttrium iron garnet (YIG) and permalloy (Py) are grown on silicon, they exhibit unexpected antiferromagnetic coupling. This finding opens up new possibilities for controlling magnetoresistance states and magnon currents in spintronic devices.
To analyze PNR data, researchers use software tools like the REDUCTUS package and REFL1D program. These tools have been successfully applied in previous studies and have been referenced in publications by NIST researchers and other groups. The development of PNR and its application to studying magnetic coupling in heterostructures represents a significant advance in understanding the fundamental properties of magnetic materials and their potential applications in spintronics and other technologies.
Keywords: magnetic thin film materials, polarized neutron reflectometry, magnetism, magnon currents
