title: Realignment of Nanocrystal Aggregates into Single Crystals as a Result of Inherent Surface Stress.
abstract: Crystallization by particle attachment is widely observed in both natural and synthetic environments. Although this form of nonclassical crystallization is generally described by oriented attachment, random aggregation of building blocks to give single-crystal products is also observed, but the mechanism of crystallographic realignment is unknown. We herein reveal that random attachment during aggregation-based growth initially produces a nonoriented growth front. Subsequent evolution of the orientation is driven by the inherent surface stress applied by the disordered surface layer and results in single-crystal formation by grain-boundary migration. This mechanism is corroborated by measurements of orientation rate versus external stress, which demonstrated a predictive relationship between the two. These findings advance our understandings about aggregation-based growth via nanocrystal blocks and suggest an approach to material synthesis that takes advantage of stress-induced coalignment.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310027, China.
authors.forename: Zhaoming
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, Zhejiang, 310027, China. panhh@zju.edu.cn.
authors.forename: Haihua
authors.initials: H
authors.lastname: Pan
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310027, China.
authors.forename: Genxing
authors.initials: G
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310027, China.
authors.forename: Yaling
authors.initials: Y
authors.lastname: Li
authors.affiliation: Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Tao
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310027, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Jin
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310027, China. rtang@zju.edu.cn.|Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, Zhejiang, 310027, China. rtang@zju.edu.cn.
authors.forename: Ruikang
authors.initials: R
authors.lastname: Tang
keywords: aggregation; calcium carbonate; crystal growth; crystal orientation; surface stress