Direct Conversion of Graphite to Diamond in Static Pressure Apparatus

Bundy, F. P.

doi:10.1126/science.137.3535.1057

Cited by 101 publications

(51 citation statements)

References 14 publications

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“…Second, covalent bonding between the two phases can occur when the surface of diamond is reconstructed thermally. Although the phases of diamond and graphite are known to coexist in surface-graphitized nanodiamond particles or during the initial nucleation stages of diamond growth [13][14][15][16] , there is no clear insight into how graphene interfaces with diamond both structurally and electronically. The metallic-sp 2 and dielectric-sp 3 interface offers the perfect environment for studying the complex interplay between electronic and lattice degrees of freedom for the creation of new functionalities.…”

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confidence: 99%

A hydrothermal anvil made of graphene nanobubbles on diamond

et al. 2013

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The hardness and virtual incompressibility of diamond allow it to be used in high-pressure anvil cell. Here we report a new way to generate static pressure by encapsulating singlecrystal diamond with graphene membrane, the latter is well known for its superior nanoindentation strength and in-plane rigidity. Heating the diamond-graphene interface to the reconstruction temperature of diamond (B1,275 K) produces a high density of graphene nanobubbles that can trap water. At high temperature, chemical bonding between graphene and diamond is robust enough to allow the hybrid interface to act as a hydrothermal anvil cell due to the impermeability of graphene. Superheated water trapped within the pressurized graphene nanobubbles is observed to etch the diamond surface to produce a high density of square-shaped voids. The molecular structure of superheated water trapped in the bubble is probed using vibrational spectroscopy and dynamic changes in the hydrogen-bonding environment are observed.

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A hydrothermal anvil made of graphene nanobubbles on diamond

et al. 2013

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“…The study of solid-solid phase transformations of materials, and their structural stabilization upon incorporation of soft materials at different scales, can be very helpful in this regard. For instance, application of pressure and temperature converts graphite to a hard diamond phase that persists at ambient conditions, allowing for a wide range of known applications (4). Upon addition of soft materials such as silicon and metals (5,6), the sintered diamond-dominant nanocomposites show improved yield strength and fracture toughness (by several orders of magnitude) without significant diminution of hardness.…”

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“…One can also perceive in the saw-like structure small facets of the rock-salt CdSe (001) surface. 4. Electronic Structure of CdSe Nanosheets Under High Pressure.…”

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Reconstructing a solid-solid phase transformation pathway in CdSe nanosheets with associated soft ligands

Wang

Wen

Hoffmann

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

124

110

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Integrated single-crystal-like small and wide-angle X-ray diffraction images of a CdSe nanosheet under pressure provide direct experimental evidence for the detailed pathway of transformation of the CdSe from a wurtzite to a rock-salt structure. Two consecutive planar atomic slips [(001) h110i in parallel and (102) h101i with a distortion angle of ∼40°] convert the wurtzite-based nanosheet into a saw-like rock-salt nanolayer. The transformation pressure is three times that in the bulk CdSe crystal. Theoretical calculations are in accord with the mechanism and the change in transformation pressure, and point to the critical role of the coordinated amines. Soft ligands not only increase the stability of the wurtzite structure, but also improve its elastic strength and fracture toughness. A ligand extension of 2.3 nm appears to be the critical dimension for a turning point in stress distribution, leading to the formation of wurtzite (001)/zinc-blende (111) stacking faults before rock-salt nucleation.phase transition | semiconductor | dimensionality R ational synthesis of materials with defined structure and properties requires a reasonably complete understanding of the associated kinetic transformations and microscopic mechanisms (1). We need to know these in order to understand how associated soft-bonded organics may tune structural stability, elastic strength, and fracture toughness (1-3). The study of solid-solid phase transformations of materials, and their structural stabilization upon incorporation of soft materials at different scales, can be very helpful in this regard. For instance, application of pressure and temperature converts graphite to a hard diamond phase that persists at ambient conditions, allowing for a wide range of known applications (4). Upon addition of soft materials such as silicon and metals (5, 6), the sintered diamond-dominant nanocomposites show improved yield strength and fracture toughness (by several orders of magnitude) without significant diminution of hardness.Many fascinating natural substances, such as human bone and other biological materials, also contain exceptionally strong building blocks (2, 3) essential to their function. The subtle interplay between soft organics and embedded brittle materials is responsible not only for enhancement of the structural stability of embedded brittle materials, but also for improvement of the yield strength and fracture toughness of assembled hierarchical organizations (2, 3).Microscopic mechanisms of transformation are difficult to determine. In bulk solids, as metastable higher energy and higher density phases nucleate in multiple domains, structural features (such as defects, microstructure, and impurities) may modify significantly the kinetics and mechanism of a phase transformation. In principle, calculations could provide the energy difference between structural polymorphs at a given pressure or temperature. But putting aside problems in computing activation barriers, there is often a large discrepancy between theory and experiment. F...

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“…The magnitude of the required bosonic quanta of energy and momenta further diminishes the probability of diamond forming. Just the bosonic rehybridization energy alone for sp 3 formation is 401.9 kJ/mol [6]. The bosonic rehybridization energy per carbon atom is equivalent to hard-ultraviolet (UVC) photons.…”

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“…Among all elements, carbon atoms manifest the most number of these most difficult bond fixation events in forming diamond. Such bond rearrangements during condensations require bosonic rehybridization of s and p orbitals with diamond (sp 3 ) requiring greater sp orbital mixing than graphite (sp 2 ). Carbon atoms require more intense bosonic collisions and interactions to form diamond than graphite.…”

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Treatise on the Resolution of the diamond problem after 200 years

Little

Roache

2008

Progress in Solid State Chemistry

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Abstract:The problem of the physicochemical synthesis of diamond spans more than 200 years, involving many giants of science. Many technologies have been discovered, realized and used to resolve this diamond problem. Here the origin, definition and cause of the diamond problem are presented. The Resolution of the diamond problem is then discussed on the basis of the Little Effect, involving novel roton-phonon driven (antisymmetrical) multi-spin induced orbital orientation, subshell rehybridization and valence shell rotation of radical complexes in quantum fluids under magnetization across thermal, pressure, compositional, and spinor gradients in both space and time. Some experimental evidence of this magnetic quantum Resolution is briefly reviewed and integrated with this recent fruitful discovery. Furthermore, the implications of the Little Effect in comparison to the Woodward-Hoffman Rule are considered. The distinction of the Little Effect from the prior radical pair effect is clarified. The better compatibility of radicals, dangling bonds and magnetism with the diamond lattice relative to the graphitic lattice is discussed. Finally, these novel physicochemical phenomena for the Little Effect are compared with the natural diamond genesis. * corresponding author; email : redge_little@yahoo.com Keywords: diamond, high pressure, plasma deposition, catalytic properties, magnetic properties. Introduction -The Diamond Problem:A long history of giants of science has defined and contributed to the solution of the diamond problem. Section 2 considers the cause of the diamond problem. The list includes Newton, Boyle, Lavoisier, Guillton, Clouet, Karazin, Despretz, Hannay, Moisson, Roozeboom, Jessup, Rossini, Tammann, Parson, Einstein, Leipunski, Bridgman, Berman, Simon, Hershey, von Platen, Lundblad, Hall, Bundy, Strong, Wentorf, Cannon, Eversole, Deryagin, Angus, Fedoseev, Setaka, Matsumoto, Yugo, Linarres, Hemley, Sumiya, and Little. On the basis of these investigators, many technologies have been considered for resolving the diamond problem. These technologies include electric arcs; metal solvents; metal catalysts; electric ovens; electric resistive heaters; anvil vices and presses; electron beams; atomic beams; x-rays, alpha, and beta irradiators; exploding media; rapid lasing and liquid nitrogen quencher; chemical vapor deposition (CVD); hydrogenous plasma and microwave apparatuses; hot filaments; flames; and recently strong magnets. Some of these technologies have resulted in partial successes by the direct method, the indirect method and the H plasma metastable method of forming diamond. The complete Resolution here considers all three of these methods along with natural diamond formation and demonstrates complete Resolution by external magnetization (using external magnetization in conjunction with these three methods and considering intrinsic magnetism in mantle Kimberlite).On this basis, the synthesis and understanding of diamond have developed along side developments in chemistry, physics and engineering dur...

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Direct Conversion of Graphite to Diamond in Static Pressure Apparatus

Cited by 101 publications

References 14 publications

A hydrothermal anvil made of graphene nanobubbles on diamond

A hydrothermal anvil made of graphene nanobubbles on diamond

Reconstructing a solid-solid phase transformation pathway in CdSe nanosheets with associated soft ligands

Treatise on the Resolution of the diamond problem after 200 years

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