This week we highlight a paper in Nature Physics by Nikolay Kardjilov and co-authors “Three-dimensional imaging of magnetic fields with polarized neutrons”.
3D tomography and microscopy with x-rays is nothing new. Neutrons, however, provide the advantage of strong scattering from magnetic spins – but microscopy with neutrons is limited due to lack of focusing optics, low brightness and monochromacity of neutron sources.
Kardjilov and co-authors present a new technique based on observing the rotation of spin polarization of neutrons as they travel through magnetic material. The result is a 3D view of local magnetization with 100-micron spatial resolution. This technique requires highly polarized and monochromatic neutron beams.