Polarized neutron reflectometry data can be found in the 'PNR' folder, which corresponds to the raw data in Figs 1a,c,e. The Two cross sections in these can be used to calculate the spin asymmetry for Figs 1b,d,e and supplementary Fig x. The reduction process can be seen by reloading into the REDUCTUS software package found at ruductus.nist.gov. Instructions on the REDUCTUS software are located at nist.gov/ncnr/data-reduction-analysis/reflectometry-software

The 'Xray' folder contains the x-ray reflectivity data for each sample as a .refl file, and the OriginPro .opju file containing the rocking curve is also included.