  The utilization of polarized neutrons is of great importance in scientific
disciplines spanning materials science, physics, biology, and chemistry.
Polarization analysis offers insights into otherwise unattainable sample
information such as magnetic domains and structures, protein crystallography,
composition, orientation, ion-diffusion mechanisms, and relative location of
molecules in multicomponent biological systems. State-of-the-art multilayer
polarizing neutron optics have limitations, particularly low specular
reflectivity and polarization at higher scattering vectors/angles, and the
requirement of high external magnetic fields to saturate the polarizer
magnetization. Here, we show that by incorporating 11B4C into Fe/Si
multilayers, amorphization and smooth interfaces can be achieved, yielding
higher neutron reflectivity, less diffuse scattering and higher polarization.
Magnetic coercivity is eliminated, and magnetic saturation can be reached at
low external fields (>2 mT). This approach offers prospects for significant
improvement in polarizing neutron optics, enabling; nonintrusive positioning of
the polarizer, enhanced flux, increased data accuracy, and further
polarizing/analyzing methods at neutron scattering facilities.
