Figure 2: Comparison between the hysteresis loops measured by XMCD and those produced by the model, as well as detailed view of the micromagnetic structure of the sample at certain temperatures and field values extracted from the model.

(a,c) Hysteresis loops, experimental and theoretical for Ni and Gd, respectively. The magnetisation has been normalised by the highest and lowest values of magnetisation within the loop to ease comparison. Shaped markers on some theoretical loops show the temperature and field values of the vector diagrams in (b). (b) Vector diagrams showing the direction of magnetisation of each atomic layer in the model system used to produce the hysteresis loops. The magnitude of the magnetisation is not shown. Black arrows represent Ni layers, red Gd, as labelled in the top left. The experimental hysteresis loops are from the same sample as that shown in Fig. 1(b,c) (behaviour 3), and has (total) Ni and Gd thicknesses of 8 nm and 6 nm, respectively.