Revealing the Symmetry of Materials through Neutron Diffraction

Magnetic materials are used in many devices in everyday life. To control their properties, we must first understand how they are ordered. This can be accomplished through neutron diffraction measurements. However, in many cases, there are too many parameters to determine the structure uniquely. Fortunately, symmetry can greatly constrain the number of parameters. Symmetry can also allow us to determine which physical properties are possible. In this review, I discuss the role of symmetry in magnetic structure determination using neutron diffraction. In this review, I will discuss both representational analysis as well as the magnetic superspace formalism. I will also discuss where the magnetic structure has been critical to understanding the fundamental science of the problem.