Prenucleation Induced by Crystalline Substrates
- 132 Downloads
Prenucleation refers to the phenomenon of atomic ordering in the liquid adjacent to the substrate/liquid interface at temperatures above the liquidus. In this paper, we have systematically investigated and holistically quantified the prenucleation phenomenon as a function of temperature and the lattice misfit between the substrate and the solid, using molecular dynamics (MD) simulations. Our results have confirmed that at temperatures above the liquidus, the atoms in the liquid at the interface may exhibit pronounced atomic ordering, manifested by atomic layering normal to the interface, in-plane atomic ordering parallel to the interface, and the formation of a 2-dimensional (2D) ordered structure (a few atomic layers in thickness) on the substrate surface. Holistic quantification of such atomic ordering at the interface has revealed that the atomic layering is independent of lattice misfit and is only slightly enhanced by reducing temperature while both in-plane atomic ordering and the formation of the 2D ordered structure are significantly enhanced by reducing the lattice misfit and/or temperature. This substrate-induced atomic ordering in the liquid may have a significant influence on the subsequent heterogeneous nucleation process.
Authors would like to thank Dr. C.M. Fang and Professor H. Assadi for constructive discussion and Dr. I. Stone for carefully reading and correcting the manuscript. The EPSRC is gratefully acknowledged for providing financial support under Grant EP/H026177/1.
- 1.K.F. Kelton and A.L. Greer: Nucleation in condensed matter: Applications in materials and biology, Pergamon, Oxford, 2010.Google Scholar
- 21.S.H. Oh, C. Scheu and M. Rühle: Korean J. Electron Microscopy Special Issue, 2006, vol. 1, pp. 19-24.Google Scholar
- 33.C.M. Fang and Z. Fan: to be submitted, 2017.Google Scholar
- 36.J.R. Hook and H.E. Hall: Solid state physics, 2nd ed., Wiley, Chichester, 1991.Google Scholar
- 38.J.P. Hirth and J. Lothe: Theory of dislocations, 2nd ed., John Wiley, New York, 1982.Google Scholar
- 39.J.X. Zhu, M. Li, R. Rogers, W. Meyer, R.H. Ottewill, STS-73 Space Shuttle Crew, W.B. Russel and P.M. Chaikin: Nature, 1997, vol. 387, pp. 883-5.Google Scholar
- 42.R.P. Jensen. PhD thesis, University of Wisconsin-Madison, US, 1998.Google Scholar
- 43.B. Jiang, H. Men and Z. Fan: to be submitted, 2017.Google Scholar
- 45.G.P. Jones: Solidification processing 1987, The Institute of Metals, London, 1988, pp. 496Google Scholar