Research Institute for Solid State Physics and Optics, P.O. Box 49, H-1525 Budapest, Hungary.
Department of Physics, University of Bergen, Allégaten 55, 7005 Bergen, Norway.
Phys Rev E. 2017 May;95(5-1):052801. doi: 10.1103/PhysRevE.95.052801. Epub 2017 May 4.
Structural aspects of crystal nucleation in undercooled liquids are explored using a nonlinear hydrodynamic theory of crystallization proposed recently [G. I. Tóth et al., J. Phys.: Condens. Matter 26, 055001 (2014)JCOMEL0953-898410.1088/0953-8984/26/5/055001], which is based on combining fluctuating hydrodynamics with the phase-field crystal theory. We show that in this hydrodynamic approach not only homogeneous and heterogeneous nucleation processes are accessible, but also growth front nucleation, which leads to the formation of new (differently oriented) grains at the solid-liquid front in highly undercooled systems. Formation of dislocations at the solid-liquid interface and interference of density waves ahead of the crystallization front are responsible for the appearance of the new orientations at the growth front that lead to spherulite-like nanostructures.
使用最近提出的（G. I. Tóth 等人，J. Phys.：Condens. Matter 26, 055001 (2014)JCOMEL0953-898410.1088/0953-8984/26/5/055001）过冷液体中晶体成核的结构方面进行了探索，该理论基于将涨落流体动力学与相场晶体理论相结合。我们表明，在这种流体动力学方法中，不仅可以实现均匀成核和非均匀成核过程，还可以实现生长前沿成核，从而在高度过冷的系统中在固液前沿形成新的（不同取向的）晶粒。在固液界面处形成位错和在结晶前沿前的密度波干扰是导致生长前沿出现新取向的原因，从而导致类似球晶的纳米结构。
