FERRIFERROMAGNETIC AND ANTIFERROMAGNETIC THIN-FILM GRATING COUPLERS FOR THIN-FILM NEUTRON WAVE-GUIDES

A new grating coupler is proposed for the coupling of neutron de Brogl ie waves into thin film neutron waveguides. The new grating coupler is a ferri- or antiferromagnetic thin film separated from the waveguide by a thin buffer film. We have shown that if the planes with the same direction of magnetic moment are not parallel to the thin film surface it is always possible to choose a well defined incident angle in orde r to couple efficiently the neutron waves diffracted by the grating in to propagating modes of the thin film waveguide.