Phase-field simulations of spiral growth during directional ternary eutectic solidification

Hötzer, Johannes; Steinmetz, Philipp; Jainta, Marcus; Schulz, Sebastian; Kellner, Michael; Nestler, Britta; Genau, Amber; Dennstedt, Anne; Bauer, Martin; Köstler, Harald; Rüde, Ulrich

doi:10.1016/j.actamat.2015.12.052

Cited by 46 publications

(20 citation statements)

References 41 publications

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“…[180,181] As in all multiphase materials, interfacial energies play a key role in eutectic microstructure evolution, and thus the effects of anisotropy in interfacial energy were studied. [186][187][188] Eutectic phase-field models have been employed to simulate many different types of eutectic material systems, including metals and ionic compounds. [182,183] The effects of the temperature profile were investigated, and a lamellar-to-rod microstructural transition was found in the directional solidification of the eutectic with the temperature gradient direction transverse to the solidification direction.…”

Section: Absorption-induced Transparency and Localized Enhanced Opticmentioning

confidence: 99%

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Template‐Directed Solidification of Eutectic Optical Materials

Kulkarni

Kohanek

Tyler

et al. 2018

Advanced Optical Materials

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polarizers, some waveguides, and many lasers. [1][2][3] Materials with powerful optical functionalities, including negative-index of refraction and optical chirality, can be realized by appropriate placement of materials with suitable properties in 2D or 3D space. [4][5][6] Light in the visible spectrum can be manipulated, although the tolerance for defects is exceedingly low at visible frequencies, and the number of materials with the appropriate properties is limited. [7,8] Most photonic crystals are fabricated by high-resolution top-down 2D patterning methods such as electron-beam lithography, interference lithography, and focused ion beam milling. [9] However, it is challenging to fabricate large-area bulk materials with these techniques, especially with intricate internal structures. [8] Additionally, many materials with promising optical properties are not compatible with these top-down patterning methods. [4,10] As work on colloidal crystals has shown, controlled self-assembly is an effective route to organizing materials into 3D architectures, which interact strongly with light. [9][10][11][12][13] Colloidal self-assembly, however, only offers a limited set of symmetries (generally those of close packed arrangements), and a spherical basis. [12] For many applications, considerably more complex structures are of interest. Particularly promising approaches for forming materials with complex internal microstructures include eutectic solidification and block copolymer self-assembly, [14][15][16][17] and materials with interesting optical properties have been reported using both approaches. These methods are advantageous due to the wide range of microstructures they form. Here, we focus on the structures formed by eutectic solidification since materials with a broader range of optical properties are available compared to that provided by block copolymers, and because the characteristic lengths of structures accessible through eutectic solidification better match the wavelengths of visible and IR light. Further, forming materials with sufficiently large characteristic dimensions for interaction with visible light by block copolymer assembly is synthetically challenging as it requires high molecular weight polymers. [18] Similarly, self-assembly of other building blocks, e.g., nanoparticles, [19,20] molecules, [21,22] and DNA, [23,24] tend to produce structures with characteristic dimensions too small to provide strong light-matter interactions (via diffractive phenomena), [2,3,25] and are thus not the emphasis of this review.Mesostructured materials can exhibit enhanced light-matter interactions, which can become particularly strong when the characteristic dimensions of the structure are similar to or smaller than the wavelength of light. For controlling visible to near-infrared wavelengths, the small characteristic dimensions of the required structures usually demand fabrication by sophisticated lithographic techniques. However, these fabrication methods are restricted to producing 2D and a limited range of 3D...

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Section: Absorption-induced Transparency and Localized Enhanced Opticmentioning

confidence: 99%

Section: Template-directed Solidification Of Eutectic Materialsmentioning

confidence: 99%

Template‐Directed Solidification of Eutectic Optical Materials

Kulkarni

Kohanek

Tyler

et al. 2018

Advanced Optical Materials

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“…Past reports have shown that eutectic spirals mostly develop a helical morphology . To determine if the same holds true for the Zn‐MgZn 2 spirals (Figure S1A,2, Supporting Information), we examined the microstructure in 3D via X‐ray nano‐tomography (nTXM).…”

Section: Resultsmentioning

confidence: 87%

“…Thus far, spiral patterns have been observed in the Al‐Th, Al‐Ag‐Cu, and Zn‐Mg alloy systems, as well as a few non‐metallic systems. These reports offer competing proposals for the mechanism of spiral growth, including different growth rates of the eutectic phases, grain rotations along the eutectic growth direction, diffusional instabilities caused by a third component, osmotic flow‐driven fingering, tilted growth in directional solidification, and thermal fluctuations . Such phenomena may occur simultaneously or sequentially over the course of crystallization, and thus it is difficult to conclusively isolate the dominant factor for spiral formation.…”

Section: Introductionmentioning

confidence: 99%

Multi‐Step Crystallization of Self‐Organized Spiral Eutectics

Moniri

Bale

Volkenandt

et al. 2020

Small

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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.

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“…Simulative research of the pattern formation in three-phase ternary eutectics with the phase-field method is conducted in 3D for idealized systems in [19][20][21][22][23] and for Al-Ag-Cu in [23][24][25][26]. In idealized systems of directionally solidified ternary eutectics, various patterns are found in [20] and the influence of the concentration of the melt and the solid-liquid interface energies on the pattern formation is identified in [23].…”

Section: Introductionmentioning

confidence: 99%

Phase-field study of the pattern formation in Al–Ag–Cu under the influence of the melt concentration

Steinmetz

Kellner

Hötzer

et al. 2016

Computational Materials Science

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In single transverse sections of directional solidified ternary eutectics, various microstructure patterns can be observed. These patterns influence the mechanical properties and it is therefore of interest to gain a better understanding of the microstructure formation process. It is assumed that local variations in the concentration of the melt lead to different patterns. To investigate this effect, large-scale three-dimensional phase-field simulations of directional solidification in the vicinity of the ternary eutectic point of Al-Ag-Cu are applied. The different arising patterns from the simulations are compared and analyzed with statistical methods. The simulations show different stable patterns within a range of ± 1% of the melt concentration around the ternary eutectic point. The same tendencies are observed in experimental micrographs.

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Phase-field simulations of spiral growth during directional ternary eutectic solidification

Cited by 46 publications

References 41 publications

Template‐Directed Solidification of Eutectic Optical Materials

Template‐Directed Solidification of Eutectic Optical Materials

Multi‐Step Crystallization of Self‐Organized Spiral Eutectics

Phase-field study of the pattern formation in Al–Ag–Cu under the influence of the melt concentration

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