Date/Time
Date(s) - 09/22/2020
3:00 pm - 4:00 pm
Categories
Kathryn Krycka, Ph.D.
Staff Scientist, NIST Center for Neutron Research
Abstract:
This talk will focus on nanoscale magnetic morphologies and inter-particle correlations that can be revealed using Small Angle Neutron Scattering. By measuring the polarization of the neutron spins before and after interaction with a sample, it is possible to additionally separate the structural and magnetic scattering contributions and resolve the magnetic scattering into components arising from moments aligned parallel and perpendicular to an external applied magnetic field. Examples include quantifying the canting angle within close-packed cobalt ferrite nanoparticles, observation of a thin magnetically canted shell of reduced stiffness within structurally homogenous ferrite nanoparticles, and measurement of exchange bias pinned spins between iron core and iron-oxide shell nanoparticles. I will also share some developments from the new vSANS instrument at the NIST Center for Neutron Research, including a recent polarized beam measurement using our high-resolution detector. This detector is capable of yielding scattering information from large structures (surveying reciprocal space down to 0.0002 inverse angstroms) and has been instrumental for detecting anti-ferromagnetic alignment within 500 nm MnCr2O4 grains.