Growth of single crystals of graphite from a carbon-iron melt

Noda, Tokiti; Sumiyoshi, Yoshihro; Ito, Noriaki

doi:10.1016/0008-6223(68)90067-5

Cited by 27 publications

(5 citation statements)

References 7 publications

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“…37 Again, anhydrous HCl or other non-oxidizing acid vapors cannot be used because HCl will produce H2 gas, both by thermal dissociation (~0.73% at 1000 °C), 38 and reaction with Ni and this H2 may etch the graphene layers. Moreover, as the remaining dissolved C in the Ni foil graphitizes as the foil is etched (discussed in detail later), the presence of H2 may complicate this process by creating vacancies or sp 3 carbon. Indeed, H2-Cl2 mixtures have been used to form nano-diamond particles or sp 3 carbons that are not wanted in our process.…”

Section: Resultsmentioning

confidence: 99%

“…Methods such as the molten flux route (>1500 °C) − or the metal–carbon solid solution route − have been explored to synthesize graphite crystals in the bulk form or as thin films. However, the graphite films generated are often heavily wrinkled, a defect that, along with grain boundaries, dislocations, and vacancies, is largely detrimental to their properties, including thermal and electrical conductivities and mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

et al. 2020

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Principal defects found in graphite films include grain boundaries and wrinkles. These defects are well known to have detrimental effects on properties such as thermal and electrical conductivities as well as mechanical properties. With a two-fold objective of synthesizing graphite films with large single crystal grains and no wrinkles, we have developed a relatively low temperature (< 1150 °C) process that involves the precipitation of graphite films from nickel-carbon solid solutions followed by in-situ etching of the nickel foil substrates with anhydrous chlorine gas to obtain near wrinkle free continuous graphite films. The size (La) distribution of lateral grains (or single crystal regions) in these highly oriented graphite films has been found to be asymmetric with the largest grains about 0.9 mm in diameter, as determined by electron backscatter diffraction (EBSD). Thus, the growth of large area graphite films with grains much larger than those reported for highly oriented pyrolytic graphite (HOPG, ~20-30 µm), and with a low density of wrinkles, as in the case of HOPG, but prepared at much lower temperatures, is reported here.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

et al. 2020

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“…9 Metals, either in the form of solid or melt, have been reportedly used to yield graphite lms with large grains by dissolution of carbon and its subsequent precipitation from metals. [10][11][12][13][14] However, such graphite lms had heavy wrinkles/kinks that were likely due to the much larger thermal contraction of the metal substrate compared to the graphite lm adhering to it upon cooling from the high temperatures used to synthesize such lms, to room temperature; 15 such signi cant defects strongly and adversely impact performance. [16][17][18] Recently, the synthesis of a single crystal graphite lm was reportedly achieved by continuous epitaxy based on single crystal nickel in isothermal environment.…”

Section: Introductionmentioning

confidence: 99%

Mirror-like and large grain graphite film: Synthesis and properties

Zhang,

Wang,

Jeon

et al. 2024

Preprint

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Graphite films with large grain sizes have been reportedly obtained by using metal as catalysts, but the obtained graphite is mostly heavily wrinkled, thus containing defects that degrade its properties. We report the synthesis of mirror-like and large-grained graphite films with only a few nano kinks and controllable dimensions, achieved by using flat Ni-Mo alloy melts of the same lateral dimensions as the metal foils used to make this alloy melt. After formation of the graphite film, we deliberately evaporated out (much of the) Ni to produce a porous metallic substrate to dramatically weaken the substrate-graphite film interaction prior to cooling down to room temperature; with this step, the graphite film then had only a few nano kinks and a mirror-like appearance. The mirror-like graphite appears to be 100% AB-stacked with millimeter-sized grains that are much larger than the multi-micron grain size of highly oriented pyrolytic graphite and rivaled in size only by a small percentage of natural graphite. Our graphite films have an electrical conductivity of 5.59 × 106 S/m at 4 K and 7.75×105 S/m at 300 K. Tensile loading of macroscale samples showed an average Young’s modulus of 969 ± 69 GPa and average fracture strength of 1.29 ± 0.203 GPa, which are, to the best of our knowledge, the highest values reported for macroscale artificial graphite materials.

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“…Carbon dioxide was reported to be e ciently converted to (sp 2 -bonded) solid carbon through bubbling into the eutectic alloy of gallium and indium at near room temperature 28 . For molten metals with moderate to relatively high solubility (iron, nickel, cobalt, others), only graphite or graphitic carbons are formed (and/or carbides) with them [29][30][31][32][33] .…”

Section: Introductionmentioning

confidence: 99%

Growth of diamond in liquid metal at 1 atmosphere pressure

Gong

Luo

Choe

et al. 2023

Preprint

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Natural diamonds were (and are) formed (some, billions of years ago) in the Earth’s upper mantle in metallic melts in a temperature range of 900–1400°C and at pressures of 5–6 GPa1,2; indeed, diamond is thermodynamically stable under high pressure and high temperature (HPHT) conditions as per the phase diagram of carbon3. Scientists at General Electric invented and used a HPHT apparatus in 1955 to synthesize diamonds from melted iron sulfide at about 7 GPa and 1600°C4–6. There is an existing paradigm that diamond can be grown using liquid metals only at both high pressure (typically 5–6 GPa) and high temperature (typically 1300–1600°C) where it is the stable form of carbon7. Here, we describe the growth of diamond crystals and polycrystalline diamond films with no seed particles using liquid metal but at 1 atmosphere pressure, and at 1025°C, breaking this paradigm. Diamond grew at the interface of liquid metal composed of gallium, iron, nickel, and silicon and a graphite crucible, by catalytic activation of methane and diffusion of carbon atoms in the subsurface region of the liquid metal. Raman spectroscopy with 13C-labeling proves that methane introduced into the growth chamber is the carbon source for many of the regions of newly grown diamond. The new growth diamonds were studied by Raman spectroscopy, scanning and transmission electron microscopy, X-ray diffraction, and photoluminescence. Growth of (metastable) diamond in liquid metal at moderate temperature and 1 atm pressure opens many possibilities for further basic science studies and for the scaling of this type of growth.

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Growth of single crystals of graphite from a carbon-iron melt

Cited by 27 publications

References 7 publications

Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

Mirror-like and large grain graphite film: Synthesis and properties

Growth of diamond in liquid metal at 1 atmosphere pressure

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