Structural studies of Fe/Pd magnetic multilayers by x-ray diffraction

Abstract

Magnetic multilayers [Fe(20 \AA{})Pd(${\mathit{t}}_{\mathrm{Pd}}$)${]}_{\mathit{n}}$ grown by electron-beam evaporation were studied by x-ray small-angle reflection and high-angle diffraction. Structural parameters such as the superlattice periods, the interfacial roughness, the interplanar distances, and the grain sizes were obtained. The experimentally measured superlattrice periods deviated from the nominal ones by a considerable amount. We found that the density of the multilayers had changed abruptly with a Pd layer thickness increase as revealed by the changes of the critical angles and superlattice periods around ${\mathit{t}}_{\mathrm{Pd}}$=30 \AA{}. We also found that the crystal structure of the Fe layer changed from bcc to fcc when the Pd layer thickness ${\mathit{t}}_{\mathrm{Pd}}$\ensuremath{\ge}36 \AA{}. Comparison of the saturated magnetization ${\mathrm{\ensuremath{\sigma}}}_{\mathit{s}}$ and the structural perfection showed that the magnetic properties of the Fe/Pd multilayer are strongly structure dependent.