Induced Local Order in Fe62Ni

One day of ISIS Polaris beamtime is requested to examine atomic superlattice order in isotopically tailored Fe62Ni and Fe62Ni(Ti); this order was developed using specialized processing protocols. While already verified by Mössbauer spectroscopy and suggested by previous neutron diffraction, the data are not perfectly convincing for high-impact dissemination. Ordered FeNi (“tetrataenite”) can store large magnetic energy by virtue of its superlattice structure. This crystallographic feature develops in Nature over billions of years and induces a strong magnetocrystalline anisotropy that is not found in the disordered alloy counterpart. Accelerating order in FeNi will foster sustainable, critical-element-free strong permanent magnets that will be transformational for sustainable, green energy applications and geopolitically influenced supply chains. These samples have been synthesized specifically for neutron diffraction studies: the 62Ni isotope furnishes a large and negative neutron scattering cross section, greatly amplifying FeNi superlattice diffraction peaks to permit clear identification of order. With the Polaris data we aim to confirm the existence of processing-induced atomic order and to establish its spatial extent. A positive result will motivate accelerated development of the processing/manufacturing approach. Polaris’ significantly higher neutron flux will facilitate collection of high-quality, high-q data from the unavoidably small mass of these samples.