We propose to study off-specular polarised neutron reflectivity from an array of CoFeB nanostructures. Many groups use Permalloy to form these types of nanostructures, however, we believe that using CoFeB offers some advantages: whilst having a similar vanishing anisotropy to Permalloy, it has a large Co content, so offering a higher magnetization, and is amorphous, so is more resistant to oxidation as it lacks grain boundaries. The nanostructure array will be designed to exhibit frustrated magnetostatic interactions (similar to a recently reported artificial spin-ice). We shall determine characteristic measures of magnetic disorder from the off-specular Bragg peak intensities that we will observe. This will be done in terms of a correlation function that incorporates the periodic physical array structure as well as the frustrated magnetic array structure.