Ce($x$Å)/Fe(10Å)

Figure: Normalised magnetisation vs temperature scans for Ce($x$Å)/Fe(10Å) multilayers.

Figure 7.3 shows the scans for Ce($x$Å)/Fe(10Å) multilayers. This set of scans has a fixed iron layer thickness of $10\ensuremath{\unskip\,\mathrm{\AA{}}}$.

The 12/10 sample shows a ferromagnetic coupling between iron layers. The magnetisation slowly decreases before dropping off more sharply at a $T_{c} = 240\pm5\ensuremath{\unskip\,\mathrm{K}}$. The magnetisation then drops linearly as for the samples with antiferromagnetically coupled iron layers in their ``paramagnetic'' region.

The 16/10 sample shows an antiferromagnetic temperature dependence. The data for this sample was particularly poor so it is difficult to tell if there is an increase in $\chi$ approaching $T_{N} = 185\pm5\ensuremath{\unskip\,\mathrm{K}}$ or if it is merely an artifact. The data does, however, favour at least a flat $\chi_{\perp}$ below $T_{N}$ as expected for such an antiferromagnet.

The 20/10 sample, as discussed in Section 7.1.1, shows anomalous behaviour and will not be compared to the rest of the set.

This set of data shows the type of interlayer coupling changing from ferromagnetic at a cerium layer thickness of $12\ensuremath{\unskip\,\mathrm{\AA{}}}$ to antiferromagnetic at $16\ensuremath{\unskip\,\mathrm{\AA{}}}$.