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Showing papers on "Diamond published in 2008"


Journal ArticleDOI
TL;DR: This paper presents a meta-analyses of the physical and chemical properties of Boron-Doped Diamond for Electrochemistry as well as a mechanistic analysis of the properties of the diamond itself and some of its applications.
Abstract: 3.6.1. Polishing and Cleaning 2663 3.6.2. Vacuum and Heat Treatments 2664 3.6.3. Carbon Electrode Activation 2665 3.7. Summary and Generalizations 2666 4. Advanced Carbon Electrode Materials 2666 4.1. Microfabricated Carbon Thin Films 2666 4.2. Boron-Doped Diamond for Electrochemistry 2668 4.3. Fibers and Nanotubes 2669 4.4. Carbon Composite Electrodes 2674 5. Carbon Surface Modification 2675 5.1. Diazonium Ion Reduction 2675 5.2. Thermal and Photochemical Modifications 2679 5.3. Amine and Carboxylate Oxidation 2680 5.4. Modification by “Click” Chemistry 2681 6. Synopsis and Outlook 2681 7. Acknowledgments 2682 8. References 2682

2,240 citations


Journal ArticleDOI
02 Oct 2008-Nature
TL;DR: An approach to nanoscale magnetic sensing is experimentally demonstrated, using coherent manipulation of an individual electronic spin qubit associated with a nitrogen-vacancy impurity in diamond at room temperature to achieve detection of 3 nT magnetic fields at kilohertz frequencies after 100 s of averaging.
Abstract: Detection of weak magnetic fields with nanoscale spatial resolution is an outstanding problem in the biological and physical sciences. For example, at a distance of 10 nm, the spin of a single electron produces a magnetic field of about 1 muT, and the corresponding field from a single proton is a few nanoteslas. A sensor able to detect such magnetic fields with nanometre spatial resolution would enable powerful applications, ranging from the detection of magnetic resonance signals from individual electron or nuclear spins in complex biological molecules to readout of classical or quantum bits of information encoded in an electron or nuclear spin memory. Here we experimentally demonstrate an approach to such nanoscale magnetic sensing, using coherent manipulation of an individual electronic spin qubit associated with a nitrogen-vacancy impurity in diamond at room temperature. Using an ultra-pure diamond sample, we achieve detection of 3 nT magnetic fields at kilohertz frequencies after 100 s of averaging. In addition, we demonstrate a sensitivity of 0.5 muT Hz(-1/2) for a diamond nanocrystal with a diameter of 30 nm.

1,817 citations


Journal ArticleDOI
02 Oct 2008-Nature
TL;DR: This work shows how magneto-optical spin detection can be used to determine the location of a spin associated with a single nitrogen-vacancy centre in diamond with nanometre resolution under ambient conditions, and demonstrates the use of a single diamond spin as a scanning probe magnetometer to map nanoscale magnetic field variations.
Abstract: Magnetic resonance imaging and optical microscopy are key technologies in the life sciences. For microbiological studies, especially of the inner workings of single cells, optical microscopy is normally used because it easily achieves resolution close to the optical wavelength. But in conventional microscopy, diffraction limits the resolution to about half the wavelength. Recently, it was shown that this limit can be partly overcome by nonlinear imaging techniques, but there is still a barrier to reaching the molecular scale. In contrast, in magnetic resonance imaging the spatial resolution is not determined by diffraction; rather, it is limited by magnetic field sensitivity, and so can in principle go well below the optical wavelength. The sensitivity of magnetic resonance imaging has recently been improved enough to image single cells, and magnetic resonance force microscopy has succeeded in detecting single electrons and small nuclear spin ensembles. However, this technique currently requires cryogenic temperatures, which limit most potential biological applications. Alternatively, single-electron spin states can be detected optically, even at room temperature in some systems. Here we show how magneto-optical spin detection can be used to determine the location of a spin associated with a single nitrogen-vacancy centre in diamond with nanometre resolution under ambient conditions. By placing these nitrogen-vacancy spins in functionalized diamond nanocrystals, biologically specific magnetofluorescent spin markers can be produced. Significantly, we show that this nanometre-scale resolution can be achieved without any probes located closer than typical cell dimensions. Furthermore, we demonstrate the use of a single diamond spin as a scanning probe magnetometer to map nanoscale magnetic field variations. The potential impact of single-spin imaging at room temperature is far-reaching. It could lead to the capability to probe biologically relevant spins in living cells.

1,814 citations


Journal ArticleDOI
TL;DR: In this paper, the use of diamond impurity centres as magnetic field sensors is explored, promising a new approach to single-spin detection and magnetic-field imaging at the nanoscale.
Abstract: Impurity centres in diamond have recently attracted attention in the context of quantum information processing. Now their use as magnetic-field sensors is explored, promising a fresh approach to single-spin detection and magnetic-field imaging at the nanoscale.

1,691 citations



Journal ArticleDOI
TL;DR: In this paper, a single spin is used as an ultrasensitive, nanoscale magnetic field sensor for magnetic imaging and spectroscopy, which can be used for the characterization of magnetic nanostructures down to the single atom level.
Abstract: We describe a scanning device where a single spin is used as an ultrasensitive, nanoscale magnetic field sensor. As this “probe spin” we consider a single nitrogen-vacancy defect center in a diamond nanocrystal, attached to the tip of the scanning device. Changes in the local field seen by the probe spin are detected by optically monitoring its electron paramagnetic resonance transition. The room-temperature scanning device may be useful for performing nanoscale magnetic resonance imaging and spectroscopy, and for the characterization of magnetic nanostructures down to the single atom level.

532 citations


Journal ArticleDOI
TL;DR: The origin of cratonic diamonds is reviewed on the basis of nearly 5000 analyses of silicate, oxide and sulphide inclusions in diamonds as mentioned in this paper, and compositional fields are defined for common minerals of the peridotitic, eclogitic and websteritic inclusion suites.

468 citations


Journal ArticleDOI
TL;DR: The combination of extreme electronic and thermal properties found in synthetic diamond produced by chemical vapor deposition (CVD) is raising considerable excitement over its potential use as a semiconductor material as discussed by the authors.

466 citations


Journal ArticleDOI
Anke Krueger1
TL;DR: The surface structure and functionalisation of diamond nanoparticles are discussed, non-covalent as well as covalent grafting of bioactive moieties is possible, and first applications of fluorescent diamond nanop particles are described.
Abstract: Nanoscale diamond particles have become an interesting material. Due to their inertness, small size and surface structure, they are well-suited for biological applications, such as labelling and drug delivery. Here we discuss the surface structure and functionalisation of diamond nanoparticles. Non-covalent as well as covalent grafting of bioactive moieties is possible, and first applications of fluorescent diamond nanoparticles are described.

398 citations


Journal ArticleDOI
TL;DR: In this article, a vapour deposited molybdenum coating on SiC powders has been used to improve the bonding strength and thermo-physical properties of the composites, using atomized Cu(X) alloys with minor additions of carbide formers.
Abstract: Thermal aspects are becoming increasingly important for the reliability of the electronic components due to the continuous progress of the electronic industries. Therefore, the effective thermal management is a key issue for packaging of high performance semiconductors. The ideal material working as heat sink and heat spreader should have a CTE of (4–8) × 10−6 K−1 and a high thermal conductivity. Metal matrix composites offer the possibility to tailor the properties of a metal by adding an appropriate reinforcement phase and to meet the demands in thermal management. Copper/SiC and copper/diamond composites have been produced by powder metallurgy. The major challenge in development of Cu/SiC is the control of the interfacial interactions. Silicon carbide is not stable in copper at the temperature needed for the fabrication of Cu/SiC. It is known that the bonding between diamond and copper is very weak in the Cu/diamond composite. Improvements in bonding strength and thermo-physical properties of the composites have been achieved by • a vapour deposited molybdenum coating on SiC powders to control interface reactions, • using atomized Cu(X) alloys with minor additions of carbide formers, e.g. X = Cr, B, to improve the interfacial bonding in Cu-diamond composites.

330 citations


Journal ArticleDOI
TL;DR: The growth and characteristics of nanocrystalline diamond thin films with thicknesses from 20nm to less than 5nm are reviewed in this paper, where it is convenient to classify these films as either ultra-nanocalstalline-diamond (UNCD) or nanocrystine-Diamond (NCD) based on their microstructure, properties, and growth environment.
Abstract: The growth and characteristics of nanocrystalline diamond thin films with thicknesses from 20 nm to less than 5 µm are reviewed. These materials contain between 95% and >99.9% diamond crystallites, the balance being made up from other forms of carbon. Within this class of materials there is a continuous range of composition, characteristics, and properties which depend on the nucleation and growth conditions. It is convenient to classify these films as either ultra-nanocrystalline-diamond (UNCD) or nanocrystalline-diamond (NCD) based on their microstructure, properties, and growth environment. In general, UNCD materials are composed of small particles of diamond ca. 2–5 nm in size with sp2-carbon bonding between the particles. UNCD is usually grown in argon-rich, hydrogen-poor CVD environments, and may contain up to 95–98% sp3-bonded carbon. NCD materials start with high density nucleation, initiating nanometer-sized diamond domains which grow in a columnar manner with the grain size coarsening with thickness. NCD is generally grown in carbon-lean and hydrogen-rich environments. NCD and UNCD exhibit an interesting range of physical properties which find use in X-ray windows and lithography, micro- and nanomechanical and optical resonators, tribological shaft seals and atomic force microscopy (AFM) probes, electron field emitters, platforms for chemical and DNA sensing, and many other applications.

Journal ArticleDOI
TL;DR: In this article, the properties of the nitrogen-vacancy center in diamond through density functional theory within the local spin density approximation by using supercell calculations were investigated and an estimate for the energy sequence of the excited states of this defect was given.
Abstract: The nitrogen-vacancy center in diamond is a promising candidate for realizing the spin qubits concept in quantum information. Even though this defect has been known for a long time, its electronic structure and other properties have not yet been explored in detail. We study the properties of the nitrogen-vacancy center in diamond through density functional theory within the local spin density approximation by using supercell calculations. While this theory is strictly applicable for ground state properties, we are able to give an estimate for the energy sequence of the excited states of this defect. We also calculate the hyperfine tensors in the ground state. The results clearly show that (i) the spin density and the appropriate hyperfine constants are spread along a plane and unevenly distributed around the core of the defect and (ii) the measurable hyperfine constants can be found within about $7\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$ from the vacancy site. These results have important implications on the decoherence of the electron spin which is crucial in realizing the spin qubits in diamond.

Journal ArticleDOI
TL;DR: In this paper, it is shown that nanocrystalline diamond (NCD) consists of facets less than 100 nm in size, whereas a second term "ultrananocrystine diamond" (UNCD) has been coined to describe material with grain sizes less than 10 nm.

Journal ArticleDOI
Anke Krueger1
TL;DR: The surface structure of nanodiamond allows for the investigation of chemical modifications of the particle surface leading to new materials for composite, biomedical or electronic applications as discussed by the authors, which is another form of carbon nanomaterials with unique properties and applications.
Abstract: Diamond nanoparticles are another form of carbon nanomaterials with unique properties and applications. This article discusses the progress made in the production, characterisation and functionalisation of this material. The surface structure of nanodiamond allows for the investigation of chemical modifications of the particle surface leading to new materials for composite, biomedical or electronic applications.

Journal ArticleDOI
TL;DR: In this paper, Coulomb blockade and Coulomb diamond measurements on an etched, tunable single-layer graphene quantum dot were performed and a charging energy of ≈3.5meV was obtained.
Abstract: We report on Coulomb blockade and Coulomb diamond measurements on an etched, tunable single-layer graphene quantum dot. The device consisting of a graphene island connected via two narrow graphene constrictions is fully tunable by three lateral graphene gates. Coulomb blockade resonances are observed and from Coulomb diamond measurements, a charging energy of ≈3.5meV is extracted. For increasing temperatures, we detect a peak broadening and a transmission increase of the nanostructured graphene barriers.

Journal ArticleDOI
TL;DR: In this article, the authors used atomized copper alloy with minor additions of chromium to increase the interfacial bonding in Cu/diamond composites by a thin nano-sized Cr 3 C 2 layer.

Journal ArticleDOI
TL;DR: In this article, a new system for loading gases at high pressure into diamond anvil cells at pressures up to 200 MPa is presented, which includes interlocks and computer control that allow it to be safely and easily operated by visiting users at the Advanced Photon Source.
Abstract: We have designed and constructed a new system for loading gases at high pressure into diamond anvil cells at pressures up to 200 MPa. The gases are used either as quasi-hydrostatic pressure media surrounding the sample or as the sample itself. The diamond cell is sealed using a clamping mechanism, which permits nearly any type of diamond anvil cell to be used. Online ruby fluorescence and video imaging systems allow in situ monitoring of the pressure and gasket deformation as the cell is sealed, resulting in a very high success rate in loading cells. The system includes interlocks and computer control that allow it to be safely and easily operated by visiting users at the Advanced Photon Source. We present preliminary X-ray diffraction data on volume compression of single-crystal magnesium oxide (MgO) in helium up to 110 GPa.

Journal ArticleDOI
TL;DR: An analysis of the figures of merit for cavity quantum electrodynamics reveals that strong coupling between an embedded diamond nitrogen-vacancy center and the cavity mode is achievable for a range of cavity dimensions.
Abstract: A photonic crystal nanocavity with a Quality (Q) factor of 1.4 x 10(6), a mode volume of 0.78(lambda/n)(3), and an operating wavelength of 637 nm is designed in a silicon nitride (SiN(x)) ridge waveguide with refractive index of 2.0. The effect on the cavity Q factor and mode volume of single diamond nanocrystals of various sizes and locations embedded in the center and on top of the nanocavity is simulated, demonstrating that Q > 1 x 10(6) is achievable for realistic parameters. An analysis of the figures of merit for cavity quantum electrodynamics reveals that strong coupling between an embedded diamond nitrogen-vacancy center and the cavity mode is achievable for a range of cavity dimensions.

Journal ArticleDOI
TL;DR: Simulation of the diffraction patterns, employing the structural factors of graphene, confirms the existence of AA graphite and creates a new graphite crystal structure containing AA(') graphene layers.
Abstract: Stacked AA graphite has been synthesized using a high-density dc plasma in hydrogen-methane mixtures. Graphene layers have been grown epitaxially with 2-1 registration between the AA graphitic edges and the (111) surface of diamond. In addition, a new graphite crystal structure containing AA′ graphene layers, where alternate planes are translated by half the hexagon width, is formed by 1-1 registry. The resulting interplanar distances of the AA graphite at the interface range from 2.20A for the 1-1 registration to 4.40A for the 2-1 registration and have been measured directly by high-resolution transmission electron microscopy (TEM). The appearance of the characteristic d-spacings, 3.55, 2.15, 1.80, 1.75 (not fully resolved), and 1.25A in the selective area diffraction patterns from the TEM, are consistent with reflections from the (001), (100), (102), (002), and (110) planes of the AA graphite. Simulation of the diffraction patterns, employing the structural factors of graphene, confirms the existence of...

Journal ArticleDOI
TL;DR: In this article, the electrical conductivity and Raman spectra of boron-doped CVD diamond films were analyzed for micro-crystalline diamond (MCD), faceted nanocrystalline (f-NCD) and "cauliflower" diamond (c -NCD), and the position of the Lorentzian contribution to the 500 cm � 1 Raman feature was used to estimate the B content.

Journal ArticleDOI
TL;DR: This work finds ultralow friction and wear for ultrananocrystalline diamond surfaces even in dry environments, and observes negligible rehybridization except for a modest, submonolayer amount under the most severe conditions (high load, low humidity).
Abstract: The impressively low friction and wear of diamond in humid environments is debated to originate from either the stability of the passivated diamond surface or sliding-induced graphitization/rehybridization of carbon. We find ultralow friction and wear for ultrananocrystalline diamond surfaces even in dry environments, and observe negligible rehybridization except for a modest, submonolayer amount under the most severe conditions (high load, low humidity). This supports the passivation hypothesis, and establishes a new regime of exceptionally low friction and wear for diamond.

Journal ArticleDOI
TL;DR: A comparison of results obtained from optical microreflectance measurements with photonic band-structure calculations reveals that it is this sophisticated microassembly of the diamond-based crystal lattice that lends Lamprocyphus augustus its macroscopically near angle-independent green coloration.
Abstract: We investigated the photonic crystal structure inside iridescent scales of the weevil Lamprocyphus augustus. By combining a high-resolution structure analysis technique based on sequential focused ion beam milling and scanning electron microscopy imaging with theoretical modeling and photonic band-structure calculations, we discovered a natural three-dimensional photonic structure with a diamond-based crystal lattice operating at visible wavelengths. Moreover, we found that within individual scales, the diamond-based structure is assembled in the form of differently oriented single-crystalline micrometer-sized pixels with only selected lattice planes facing the scales' top surface. A comparison of results obtained from optical microreflectance measurements with photonic band-structure calculations reveals that it is this sophisticated microassembly of the diamond-based crystal lattice that lends Lamprocyphus augustus its macroscopically near angle-independent green coloration.

Journal ArticleDOI
TL;DR: A review of the state of the art of chemical, photochemical and electrochemical strategies for the grafting of different organic functionalities on diamond surfaces can be found in this article.
Abstract: Functionalization of diamond surfaces holds considerable promise from both fundamental and applied research aspects. This review summarizes briefly the state of the art of chemical, photochemical and electrochemical strategies for the grafting of different organic functionalities on diamond. Depending on the sought-after application and the desired physical property of diamond, halogenated, aminated, carboxylated and oxidized diamond surfaces have been proposed. After a brief introduction, the review is primarily divided into two parts, presenting chemical functionalisation strategies used on oxygen-terminated diamond, followed by methods used for the formation of C–C, C–X and C–N bonds on hydrogen-terminated diamond.

Journal ArticleDOI
TL;DR: In this paper, a detailed theoretical analysis of the electron spin decoherence in single nitrogen-vacancy defects in ultrapure diamond is presented, which is due to the interactions with nuclear spins in the diamond lattice.
Abstract: We present a detailed theoretical analysis of the electron spin decoherence in single nitrogen-vacancy defects in ultrapure diamond. The electron spin decoherence is due to the interactions with $^{13}\text{C}$ nuclear spins in the diamond lattice. Our approach takes advantage of the low concentration (1.1%) of $^{13}\text{C}$ nuclear spins and their random distribution in the diamond lattice by an algorithmic aggregation of spins into small, strongly interacting groups. By making use of this disjoint cluster approach, we demonstrate a possibility of nontrival dynamics of the electron spin that cannot be described by a single time constant. This dynamics is caused by a strong coupling between the electron and few nuclei and exhibits large variations depending on the distribution of $^{13}\text{C}$ nuclei surrounding each individual electronic spin. This results, in particular, in a substantial echo signal even at microsecond time scales. Our results are in good agreement with recent experimental observations.

Journal ArticleDOI
TL;DR: In this paper, the first excited state sublevel structure of single nitrogen-vacancy (NV) color centres in diamond was shown to be an orbital doublet, where one branch supports an efficient cycling transition, while the other can simultaneously support fully allowed optical Raman spin-flip transitions.
Abstract: We map out the first excited state sublevel structure of single nitrogen-vacancy (NV) colour centres in diamond. The excited state is an orbital doublet where one branch supports an efficient cycling transition, while the other can simultaneously support fully allowed optical Raman spin-flip transitions. This is crucial for the success of many recently proposed quantum information applications of the NV defects. We further find that an external electric field can be used to completely control the optical properties of a single centre. Finally, a group theoretical model is developed that explains the observations and provides good physical understanding of the excited state structure.

Journal ArticleDOI
TL;DR: In this article, an emission band in the infrared (IR) is associated with a transition within the negative nitrogen-vacancy centre in diamond, and uniaxial stress and magnetic field measurements indicate that the emissions are associated with the transition between 1E and 1A1 singlet levels.
Abstract: An emission band in the infrared (IR) is shown to be associated with a transition within the negative nitrogen-vacancy centre in diamond. The band has a zero-phonon line at 1046?nm, and uniaxial stress and magnetic field measurements indicate that the emission is associated with a transition between 1E and 1A1 singlet levels. Inter-system crossing to these singlets causes the spin polarization that makes the NV- centre attractive for quantum information processing, and the IR emission band provides a new avenue for using the centre in such applications.

Journal ArticleDOI
TL;DR: Nanometre-sized isolated inclusions have been studied in four cloudy octahedral diamonds from the Internatsionalnaya and one from the Yubileynaya mines (Yakutia).
Abstract: Nanometre-sized isolated inclusions have been studied in four cloudy octahedral diamonds from the Internatsionalnaya and one from the Yubileynaya mines (Yakutia). Transmission electron microscopy (TEM) techniques such as electron diffraction, analytical electron microscopy (AEM), electron energy-loss spectroscopy (EELS) and high-resolution electron microscopy (HREM) were applied as well as line scan and elemental mapping of the samples. All crystals exhibit octahedral external habit with opaque central cuboid cores that contain numerous nano-inclusions. All nano-inclusions in the size range between 30 and 800 nm reflect the diamond habit and are considered primary, syngenetic to host diamond. They are composed of multi-phase assemblages, which include solid phases (silicates, oxides, carbonates), brines (halides), and fluid bubbles. These inclusions are relatively homogeneous in composition and contain distinguishable crystalline and fluid phases. Al-bearing high-Mg silicate, dolomite, Ba-Sr carbonate, phlogopite, ilmenite, ferropericlase, apatite, magnetite, K-Fe sulfides (djerfisherite?) and kyanite have been identified as crystalline mineral phases by electron diffraction patterns, except the Ba-Sr carbonate. Several phases, including CaF 2 and clinohumite-like phases, have never been reported as inclusions in diamond. The halide phase was KCl. Bubbles contained high K, Cl, O, P and less S, Ba, Si, Ti components. Carbonates were identified in TEM foils from all studied diamonds. They occur in all assemblages with silicates, oxides, and sulfides and show a general enrichment in incompatible elements such as Sr and Ba. Some elemental variations may be explained by fractional crystallization of fluid/melt or mixing of fluids with different compositions (carbonatitic, hydrous-silicic, brines).

Journal ArticleDOI
TL;DR: In this paper, a method for preparing ultrathin single-crystal diamond membranes suitable for post-processing and liftout is reported, which can also be used for fabricating various structures including Bragg gratings and whispering gallery mode resonators.
Abstract: A method for preparing ultrathin single-crystal diamond membranes suitable for post-processing and liftout, is reported. The proposed method used single-crystal diamond substrates and two-energy ion implant process for the fabrication of thin diamond membranes. Two ion-implant process was used in this method to prepare two different damage layers within diamond sample. This method can be used for preparing integrated quantum-photonic structure based on color center in diamond. This method can also be used for fabricating various structures including Bragg gratings and whispering gallery mode resonators. A significant application of the diamond nanostructures is to fabricate the micro- and nanoscale cantilevers. It was also observed that the fabricated single-crystal diamond are suitable for another FIB processing.

Journal ArticleDOI
TL;DR: In this article, the compressible properties of the selected 5d transition metal carbides with hexagonal tungsten carbide-type structure were studied by first-principles calculations and it was shown that the incompressibility of ReC exceeds that of diamond under higher pressure.
Abstract: The compressible behaviors of the selected 5d transition metal carbides MC (M=W,Re,Os,Ir) with hexagonal tungsten carbide-type structure were studied by first-principles calculations. Results indicate that the incompressibility of ReC exceeds that of diamond under higher pressure. The calculated method for hardness of crystals with partial metallic bonding is suggested and the calculated results indicate that hexagonal ReC crystal possesses excellent mechanical properties.

Patent
05 Feb 2008
TL;DR: In this paper, a diamond body comprising a matrix phase of bonded together diamond crystals formed at high pressure/high temperature conditions with a catalyst material is treated to remove the catalyst material disposed within interstitial regions, rendering it substantially free of the catalyst materials used to initially sinter the body.
Abstract: Polycrystalline diamond constructions include a diamond body comprising a matrix phase of bonded together diamond crystals formed at high pressure/high temperature conditions with a catalyst material. The sintered body is treated remove the catalyst material disposed within interstitial regions, rendering it substantially free of the catalyst material used to initially sinter the body. Accelerating techniques can be used to remove the catalyst material. The body includes an infiltrant material disposed within interstitial regions in a first region of the construction. The body includes a second region adjacent the working surface and that is substantially free of the infiltrant material. The infiltrant material can be a Group VIII material not used to initially sinter the diamond body. A metallic substrate is attached to the diamond body, and can be the same or different from a substrate used as a source of the catalyst material used to initially sinter the diamond body.