Growth and structure characterization of EuSi 2 films and nanoislands on vicinal Si(001) surface

Anomalous Lattice Dynamics ofEuSi2Nanoislands: Role of Interfaces Unveiled

“…Epitaxial EuSi 2 samples with nominal Eu coverages of 20.0 (bulk-like film), 5.0 (thin film), 1.0 (islands), and 0.26 (islands) nm, hereinafter referred to as A, B, C, and D, respectively, were prepared by deposition of metallic Eu on the vicinal Si(001) surface at 873 K and postgrowth annealing at 973 K for 10 min [30][31][32]. For the lowest coverages these growth conditions ensure the formation of islands with high surface density.…”

“…For the lowest coverages these growth conditions ensure the formation of islands with high surface density. An additional sample labeled E, with a coverage of 0.26 nm, was prepared by Eu deposition at 673 K and postgrowth annealing at 873 K for 10 min, resulting in the formation of isolated EuSi 2 islands with low surface density [31]. The in situ nuclear inelastic scattering experiment [33,34] was performed using the ultrahigh vacuum system [35] at the Nuclear Resonance beamline ID18 [36] of the ESRF on the nuclear transition in 151 Eu with energy 21.541 keV and an energy resolution of 1.2(1) meV [37].…”

“…rare-earth disilicides are formed on the Si(001) by 45 • rotation of their unit cell with respect to that of Si. In the case of EuSi 2 this reduces the lattice mismatch from 20.8% (expansion) to 12% (compression) [31]. The influence of epitaxial strain field on the crystal structure and surface morphology was investigated in detail for ErSi 2 nanoislands and nanowires by high resolution transmission electron microscopy [44].…”

“…In order to evaluate the influence of these two intrinsically different interfaces on the lattice dynamics sample E, containing the same amount of Eu as sample D, was investigated. Unlike sample D, however, the growth protocol [31] of this sample ensures the formation of isolated EuSi 2 nanoislands with average sizes: 92(5) × 77(5) × 22(2) nm 3 and very low surface density, as evidenced by the AFM image shown in fig. 3(c).…”

A portable ultrahigh-vacuum system for advanced synchrotron radiation studies of thin films and nanostructures: EuSi2nano-islands

“…vicinal substrate with a miscut of 4 towards[110]. Details of the growth procedure can be found elsewhere(Seiler et al, 2014).…”