Atomistics of pre-nucleation layering of liquid metals at the interface with poor nucleants

DOI: 10.1038/s42004-018-0104-1

Authors: Sida Ma (Tsinghua University) , Adam J. Brown (University of Leicester) , Rui Yan (Tsinghua University) , Ruslan L. Davidchack (University of Leicester) , Paul B. Howes (University of Leicester) , Chris Nicklin (Diamond Light Source) , Qijie Zhai (Shanghai University) , Tao Jing (Tsinghua University) , Hongbiao Dong (University of Leicester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Communications Chemistry , VOL 2

State: Published (Approved)
Published: January 2019
Diamond Proposal Number(s): 12083 , 6663

Abstract: Liquid layering at heterogeneous solid/liquid interfaces is a general phenomenon, which provides structural templates for nucleation of crystalline phases on potent nucleants. However, its efficacy near poor nucleants is incompletely understood. Here we use a combination of X-ray crystal truncation rod analysis and ab initio molecular dynamics to probe the pre-nucleation liquid layering at the sapphire–aluminium solid/liquid interface. At the sapphire side, a ~1.6 aluminium-terminated structure develops, and at the liquid side, two pre-nucleation layers emerge at 950 K. No more pre-nucleation layer forms with decreasing temperature indicating that nucleation of crystalline aluminium through layer-by-layer atomic adsorption of liquid atoms is not favoured. Instead, the appearance of stochastically-formed nuclei near the substrate is supported by our experiments. Nucleation on poor nucleants is dominated by the stochastic nucleation events which are substantially influenced by the pre-nucleation layers that determine the surface structure in contact with the nuclei.

Journal Keywords: Atomistic models; Characterization and analytical techniques; Metals and alloys

Subject Areas: Chemistry


Instruments: I07-Surface & interface diffraction

Documents:
s42004-018-0104-1.pdf