Characterization of interlayer coupling in YIG/Py bilayer using polarized neutron reflectometry

The substrate size was 10×10 mm2. The room temperature neutron reflectivity curves were recorded at room temperature as the function of momentum transfer Qz = 4sin/, where is the neutron wavelength and is the incident angle between the neutron beam and the film plane.

To access a broad momentum transfer range, reflected neutrons were collected at different incident angles. Both R++ and R-- were recorded when neutrons with spins parallel or antiparallel to the applied fields (corresponding to the spin-up and spin-down neutrons), respectively. PNR data were fitted to a model (including the layer thickness and chemical roughness) that was obtained by XRR fitting using the software GenX.