Formation of a single quasicrystal upon collision of multiple grains

TL;DR

This study demonstrates the formation of a single large decagonal quasicrystal from multiple grains through real-time imaging and simulations, revealing mechanisms of coalescence and potential for large-scale fabrication.

Contribution

It introduces a novel method of creating single quasicrystals by collision and coalescence of multiple grains, supported by experimental and computational analysis.

Findings

Single quasicrystal formation observed via 3D imaging.

Coalescence facilitated by phasons at small misorientation.

Simulations elucidate kinetics and misorientation effects.

Abstract

Quasicrystals exhibit long-range order but lack translational symmetry. When grown as single crystals, they possess distinctive and unusual properties owing to the absence of grain boundaries. Unfortunately, conventional methods such as bulk crystal growth or thin film deposition only allow us to synthesize either polycrystalline quasicrystals or quasicrystals that are at most a few centimeters in size. Here, we reveal through real-time and 3D imaging the formation of a single decagonal quasicrystal arising from a hard collision between multiple growing quasicrystals in an Al-Co-Ni liquid. Through corresponding molecular dynamics simulations, we examine the underlying kinetics of quasicrystal coalescence and investigate the effects of initial misorientation between the growing quasicrystalline grains on the formation of grain boundaries. At small misorientation, coalescence occurs following rigid rotation that is facilitated by phasons. Our joint experimental-computational discovery paves the way toward fabrication of single, large-scale quasicrystals for novel applications.