X-Ray Magnetic Scattering from Nonmagnetic Lu in a DyLu Alloy

We have detected the presence of a spin-density wave (SDW) induced in the conduction band of a D${\mathrm{y}}_{0.60}$L${\mathrm{u}}_{0.40}$ thin film alloy that orders as a ${\mathit{c}-\mathrm{a}\mathrm{x}\mathrm{i}\mathrm{s}\mathrm{h}\mathrm{e}\mathrm{l}\mathrm{i}\mathrm{m}\mathrm{a}\mathrm{g}\mathrm{n}\mathrm{e}\mathrm{t}.\mathrm{B}\mathrm{y}\mathrm{t}\mathrm{u}\mathrm{n}\mathrm{i}\mathrm{n}\mathrm{g}\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{i}\mathrm{n}\mathrm{c}\mathrm{i}\mathrm{d}\mathrm{e}\mathrm{n}\mathrm{t}\mathrm{x}-\mathrm{r}\mathrm{a}\mathrm{y}\mathrm{e}\mathrm{n}\mathrm{e}\mathrm{r}\mathrm{g}\mathrm{y}\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{h}\mathrm{e}\mathit{L}}_{\mathrm{III}}$ edges, we exploit the species sensitivity of x-ray resonant magnetic scattering to isolate the contribution of each element individually. As Lu has a filled 4f shell, magnetic intensity observed at that resonance reflects the polarization of the 5d orbitals in the helical SDW. The SDW amplitude is of order 0.2 ${\mu }_B/$atom. Complementary neutron data show that the temperature dependence of the induced Lu intensity and its wave vector follow that of the total moment.