Growth of rare-earth single crystals by molecular beam epitaxy: The epitaxial relationship between hcp rare earth and bcc niobium

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.

Laser joining of NiTi to Ti6Al4V using a Niobium interlayer

“…The eutectic isotherm is 140 C below the congruent melting temperature of NiTi (1310 C). Spontaneous melting occurred with the pure Niobium being in intimate contact with NiTi at the high temperatures, and upon solidification two phases were formed: austenitic NiTi and bcc-Nb [42].…”

Probing the spiral magnetic phase in 6 nm textured erbium using polarised neutron reflectometry

“…Growth rates were calibrated by fitting to Keissig fringes obtained by X-ray reflectometry to Nb films, and bilayers of Nb/Lu and trilayers of Nb/Er/Lu. The Nb was grown first as it has been shown to be an effective buffer layer for the growth of rare-earth metals [13]. The Nb/Er interface is known to be sharp due to the lack of alloying and intermixing between Nb and Er [14].…”

“…As the out-of-plane grain size approximately matches the film thickness, it is assumed this is not the case, and that any strain in the Er layer is uniform. The Er grows epitaxially on the most densely packed Nb (110) distances along these axes [13]. While direct measurement of the in-plane lattice parameters…”

Strain-induced modification of magnetic structure and new magnetic phases in rare-earth epitaxial films

“…They were grown on a 0.4 mm thick (1 1 0) sapphire substrate which was degreased and then heated to 850 • C for 1 h in the growth chamber. Following the method proposed by Kwo et al [12] for rare earth with hexagonal structure, the substrate was first covered by a 50 nm thick bcc Nb buffer layer deposited at 800 • C. The growth direction is [1 1 0]. When Nb is deposited at high temperature, the surface is reconstructed due to chemisorbed oxygen.…”