Ce/Fe Multilayers

Multilayers containing cerium display many interesting properties[38], particularly as a result of its delocalised $4f$ electrons and their interactions with the $3d$ electrons of the transition metals. The hybridisation of the two shells is seen to induce a small magnetic moment on interface cerium atoms.[39]

The Ce/Fe multilayers studied in this section were fabricated by P. Boni and S. Tixier at the Laboratory for Neutron Scattering, Switzerland, using DC sputtering using a Leybold Z600 high vacuum system onto silicon substrates. These were characterised and studied using CEMS by G.S. Case[3], the results of which will be compared to the data acquired in this thesis.

Table 7.1: Sample thicknesses, areas and volumes. ``$-$'' denotes a sample from which magnetometry data has been taken but whose area was not measured.

$$^2 ^3 ^3 ^3$$

$$^{-4} ^{-4} ^{-4}$$

$$\left[\mathrm{Ce}(12\,\mathrm{\AA{}})/\mathrm{Fe}(10\,\mathrm{\AA{}})\right]_{60} - - - -$$ 12/10

$$\left[\mathrm{Ce}(16\,\mathrm{\AA{}})/\mathrm{Fe}(10\,\mathrm{\AA{}})\right]_{60} 4.07 3.91 2.44 6.35$$ 16/10

$$\left[\mathrm{Ce}(20\,\mathrm{\AA{}})/\mathrm{Fe}(10\,\mathrm{\AA{}})\right]_{60} 4.40 5.28 2.64 7.92$$ 20/10

$$\left[\mathrm{Ce}(20\,\mathrm{\AA{}})/\mathrm{Fe}(15\,\mathrm{\AA{}})\right]_{60} 8.80 10.56 7.92 18.48$$ 20/15

$$\left[\mathrm{Ce}(20\,\mathrm{\AA{}})/\mathrm{Fe}(17\,\mathrm{\AA{}})\right]_{60} - - - -$$ 20/17

$$\left[\mathrm{Ce}(20\,\mathrm{\AA{}})/\mathrm{Fe}(20\,\mathrm{\AA{}})\right]_{60} - - - -$$ 20/20

$$\left[\mathrm{Ce}(27\,\mathrm{\AA{}})/\mathrm{Fe}(15\,\mathrm{\AA{}})\right]_{60} 2.86 4.64 2.58 7.21$$ 27/15

$$\left[\mathrm{Ce}(27\,\mathrm{\AA{}})/\mathrm{Fe}(20\,\mathrm{\AA{}})\right]_{60} 8.02 12.99 9.46 22.45$$ 27/20

$$\left[\mathrm{Ce}(40\,\mathrm{\AA{}})/\mathrm{Fe}(20\,\mathrm{\AA{}})\right]_{60} 8.96 21.50 10.75 32.26$$ 40/20

All of the samples studied are listed in Table 7.1, with the sample composition, label, and, where available, the sample area allowing the calculation of volumes for normalising the magnetisation to the sample size. All applied field measurements were performed with the applied field parallel to the plane of the sample.