2014/03/02 by P. Süle, Süle, P., M. Menyhárd +1
Engineering · Materials Science · Physics and Astronomy · #Advanced Materials Characterization Techniques #FOS: Physical sciences #Fusion materials and technologies #Ion-surface interactions and analysis #Materials Science (cond-mat.mtrl-sci) #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.1403.0237
12 pages, 5 figures, 1 table, written in 2007, uploaded this year. arXiv admin note: text overlap with arXiv:cond-mat/0605566, arXiv:0802.2220
arxiv created 2014/03/02 · openalex publication_date 2014/03/02 · arxiv updated 2014/03/04 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Probing the anomalous nanoscale intermixing using molecular dynamics (MD) simulations in Pt/Ti bilayer we characterize the superdiffusive nature of interfacial atomic transport. In particular, the low-energy (0.5 keV) ion-sputtering induced transient enhanced intermixing has been studied by MD simulations. \em Ab initio density functional calculations have been used to check and reparametrize the employed heteronuclear interatomic potential. We find a robust intermixing in Pt/Ti driven by nanoscale mass-anisotropy . The sum of the square of atomic displacements ⟨ R2 ⟩ asymptotically scales nonlinearly (⟨ R2 ⟩ ∝ t2), where t is the time of ion-sputtering, respectively which is the fingerprint of superdiffusive features. This anomalous behavior explains the high diffusity tail in the concentration profile obtained by Auger electron spectroscopy depth profiling (AES-DP) analysis in Pt/Ti bilayer (reported in ref.: P. Süle, et al., J. Appl. Phys., 101, 043502 (2007)). In Ti/Pt bilayer a linear time scaling of ⟨ R2 ⟩ ∝ t has been found at the Ti/Pt interface indicating the suppression of superdiffusive features. These findings are inconsistent with the standard ion-mixing models. Instead a simple accelerative effect of the downward fluxes of energetic particles on the unidirectional fluxes of preferential intermixing of Pt atoms seems to explain the enhancement of interfacial broadening in Pt/Ti. Contrary to this in Ti/Pt the fluxes of recoils are in counterflow with intermixing Pt atoms and hence slows down the nanoscale mass-effect driven ballistic preferential mobility of Pt atoms.