Abstract
High-quality rare-earth (RE) single-crystal films of yttrium (Y) and gadolinium (Gd) were successfully grown with the metal molecular beam epitaxy technique on a bcc Nb single-crystal film which serves as a buffer layer to the sapphire substrates. With reflection high-energy electron diffraction, the hcp RE (0001) was found to grow epitaxially on the (110) Nb in the Nishiyama-Wasserman orientation. The regrowth of Nb on this RE (0001) surface yielded the (110) orientation with 120°in-plane domains. These epitaxial relationships suggest the possibility of fabricating an ultrathin, coherent crystalline superlattice in the Nb (110)/ RE (0001) system.