title: Freezing of Lennard-Jones fluid on a patterned substrate.
abstract: Using molecular dynamics simulations, we study freezing of Lennard-Jones particles at commensurate substrate with triangular pattern. Throughout the box particles freeze onto the substrate and form close-packed layers. For the moderately attractive substrates, an intermediate hexatic phase between liquid and crystal is detected in the first two layers where the hexatic-solid freezing process is continuous while, counterintuitively, the liquid-hexatic process is of first order. Moreover, we observe that liquid-hexatic and hexatic-solid transitions shift towards higher temperatures with the attraction strength increasing. By contrast, the liquid-hexatic transition shifts faster than the hexatic-solid process, significantly widening the temperature range of the hexatic phase. When this phenomenon appears, freezing in the bulk always proceeds through a first-order transition at the same temperature. In addition, changes in the average structural order (three-dimensional) of the layers indicate that freezing processes in layers near substrates seem to cost the structural order of the bulk particles in their vicinity, and an intermediate prestructural cloud of medium-ordered particles is always observed before the layering freezing.
authors.affiliation: School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China and Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Shuming
authors.initials: S
authors.lastname: Peng
authors.affiliation: Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.affiliation: Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Liang
authors.affiliation: School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Chubin
authors.initials: C
authors.lastname: Wan
authors.affiliation: Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zheng
authors.affiliation: School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ju
mesh_terms: D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D005615:Freezing; D008956:Models, Chemical; D008958:Models, Molecular; D044367:Phase Transition; D012212:Rheology / Q000379:methods*; D012996:Solutions / Q000737:chemistry*
chemical_list: D012996:Solutions