Growth, structural study, and thermal stability of metallic Al/Nb superlattices

Al/Nb multilayers with a chemical modulation wavelength Λ of 20–400 Å were fabricated by evaporation in an ultrahigh-vacuum system. The structures of the multilayers were studied using x-ray diffraction, Auger sputtering, and reflected high-energy electron diffraction. Al and Nb form metallic superlattices with Al(111) and Nb(110) textures. Depending on the thickness ${\mathit{D}}_{\mathrm{Al}}$ of the aluminum single layers, we found a different behavior of the thermal stability of these multilayers, which is explained by the formation of an intermetallic compound at the interface region.