Magnetic induction and domain walls in magnetic thin films at remanence

Abstract

Magnetic domain walls in thin films can be well analysed using polarized neutron reflectometry. Well defined streaks in the off-specular spin-flip scatteringmaps are explained by neutron refraction at perpendicularN´eelwalls. The position of the streaks depends only on the magnetic induction within the domains, whereas the intensity of the off-specularmagnetic scattering depends on the spin-flip probability at the domain walls and on the average size of the magnetic domains. This effect is fundamentally different and has to be clearly distinguished from diffuse scattering originating from the size distribution of magnetic domains. Polarized neutron reflectivity experimentswere carried out using a 3He gas spin filter with a analysing power as high as 96% and a neutron transmission of approximately 35%. Furthermore, the off-specular magnetic scatteringwas enhanced by using neutron resonance and neutron standingwave techniques.