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Multi‐Step Crystallization of Self‐Organized Spiral Eutectics
Author(s) -
Moniri Saman,
Bale Hrishikesh,
Volkenandt Tobias,
Wang Yeqing,
Gao Jianrong,
Lu Tianxiang,
Sun Kai,
Ritchie Robert O.,
Shahani Ashwin J.
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201906146
Subject(s) - crystallization , eutectic system , materials science , metastability , spiral (railway) , nucleation , chemical physics , phase (matter) , self organization , nanotechnology , crystallography , chemical engineering , composite material , microstructure , chemistry , thermodynamics , computer science , mechanical engineering , physics , organic chemistry , engineering , artificial intelligence
A method for the solidification of metallic alloys involving spiral self‐organization is presented as a new strategy for producing large‐area chiral patterns with emergent structural and optical properties, with attention to the underlying mechanism and dynamics. This study reports the discovery of a new growth mode for metastable, two‐phase spiral patterns from a liquid metal. Crystallization proceeds via a non‐classical, two‐step pathway consisting of the initial formation of a polytetrahedral seed crystal, followed by ordering of two solid phases that nucleate heterogeneously on the seed and grow in a strongly coupled fashion. Crystallographic defects within the seed provide a template for spiral self‐organization. These observations demonstrate the ubiquity of defect‐mediated growth in multi‐phase materials and establish a pathway toward bottom‐up synthesis of chiral materials with an inter‐phase spacing comparable to the wavelength of infrared light. Given that liquids often possess polytetrahedral short‐range order, our results are applicable to many systems undergoing multi‐step crystallization.