Neutron techniques for the observation of ferro- and antiferromagnetic domains

Abstract

Neutrons are, because of their magnetic moment, a unique probe for the investigation of magnetic domains. They can be used to distinguish ferromagnetic domains through Larmor precession in simple transmission, and both ferro- and antiferromagnetic domains from Bragg diffraction experiments. This paper tries to review the neutron studies that were made on domains either in a statistical approach to get figures on the average size or population of domains, or in the more recent local approach in which maps or pictures of the domains are obtained. Neutron diffraction topography, in which the single-crystal sample is imaged through Bragg diffraction, is the main local approach technique. It has been used till now to investigate domains in chromium, nickel oxide and silicon-iron. New observations of antiferromagnetic domains in NiO and MnF 2 are presented.