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The static electric dipole–dipole coupling between donor–acceptor pairs (DAPs) in wide-bandgap semiconductors has recently emerged as a means of realizing a quantum science platform through optically controllable, long-range interactions between defects in the solid state. In this work, we generalize DAPs to consider arbitrary dopant populations and demonstrate that the charge of the NV center in diamond is well suited for quantum science. Explicitly, we leverage experimental results [see Z. Yuan et al., PRR 2, 033263 (2020)] to show that shallow NV centers can be efficiently initialized to a given relative population of the negative and neutral charge states and that modulating the surface termination would allow for control of the timescale over which the initialization and subsequent computations would occur. Furthermore, we argue that the observation of electroluminescence from the neutral charge state of the NV center [see N. Mizuochi et al., Nat. Photon. 6, 299 (2012)], but not from the negative charge state, implies the ability to interface with the NV center's charge in a manner analogous to the spin interface enabled by the spin-state dependent fluorescence of the NV center. [ABSTRACT FROM AUTHOR]

A precise description of the thermodynamic states of gaseous and solid detonation products is essential when using thermodynamic calculations to determine the detonation performance and destructive power of explosives. For high oxygen-lean explosives (the oxygen contained in explosives is insufficient to completely oxidize combustible elements and excess solid carbon will be generated in the detonation products), the phase state of solid carbon product affects the Chapman–Jouguet (CJ) detonation performance parameters, reaction zone, and energy release process. However, the recovery of detonation products demonstrates that the actual detonation carbon product is primarily a mixed state of diamond/graphite stack, as opposed to the existing thermodynamic codes, which essentially treat detonation carbon as single-phase carbon. To understand the thermodynamic effect of the mixed carbon phase state on the non-ideal detonation behavior, in this work, the matching relationship among the VINET equation of state parameters, thermodynamic potential parameters of the solid products of the equivalent system and the phase mixed system was constructed by using the nonlinear fitting method. The relationship between the carbon phase composition at the CJ point and the explosive composition structure was researched. Investigations were conducted into how the mixed carbon phase affected the volume and content of gas products as well as the composition at CJ points. Diamond formation in products is good for enhancing explosive's working capacity. Based on mixed-state potential parameters, the correlation mechanism between the mixed carbon phase and the chemical reaction zone was investigated, and it was found that intramolecular carbon/intermolecular carbon and more detonation graphite/diamond products all would lead to the extension of the reaction zone. [ABSTRACT FROM AUTHOR]

Density functional theory was employed to examine the adsorption and thermal evolution of nitrogen species on diamond(111) impacted by microwave N2 plasma. On bare domains of diamond, as represented by the models of C(111)-2 × 1 and graphite-like C(111), N2(ad) is identified as the major surface species; the desorption of N2(ad) proceeds on both models via a concerted process of breaking two C–N bonds. By contrast, there is evidence of the formation of (NH)2(ad) via the insertion reaction of microwave N2 plasma on hydrogenated domains of diamond, as represented by the models of C(111)-2 × 1-H and C(111)-1 × 1-H. Interestingly, contrasting dynamics of desorption of (NH)2(ad) are presented on these two models, that is, via sequential breaking of two C–N bonds on C(111)-2 × 1-H and via concerted breaking of both C–N bonds on C(111)-1 × 1-H. Our results demonstrate that the observed diversity of surface nitrogen species in composition, bonding, vibration, and desorption in prior experiments is linked to domains of a variety of surface terminations and reconstructions on diamond(111). [ABSTRACT FROM AUTHOR]

The authors implanted P atoms at 50 and 140-keV energies with respective fluences of 1 × 10 14 and 2 × 10 14 /cm 2 into diamond thin films synthesized by chemical vapor deposition on the type-Ib diamond substrate formed by high-pressure and high-temperature conditions. The occupational sites of implanted P atoms were determined in each processing stage of P implantation, ion-beam-induced epitaxial crystallization (IBIEC) annealing by 3-MeV-Ne 2 + ion irradiation at 750 ° C, and thermal annealing at 850 ° C in vacuum, by quantitatively comparing the random and channeling yields in Rutherford backscattering (RBS) measurements. In the analysis of RBS spectra, simulated distributions were fitted to the experimentally obtained spectra and we quantitatively identified the occupational sites and ratio of implanted P atoms. In addition, we investigated the diffusion phenomenon of implanted P atoms during annealing processes from the depth profile of scattered He ions. Consequently, the averaged occupational ratio in the substitutional lattice site was stably recorded around 50%. From the depth profile in the RBS spectra, thermal diffusion of implanted P atoms was clearly observed during the last thermal annealing after MeV-IBIEC annealing. We finally discuss the potentials of the MeV-IBIEC irradiation at relatively low temperatures applying to useful and credible annealing methods for electrical activation as well as recovery of damaged crystallinity. [ABSTRACT FROM AUTHOR]

In this work, nitrogen vacancy (NV) centers of high nitrogen diamond implanted with arsenic ions were investigated by photoluminescence spectroscopy. The transition of the NV center charge state was discussed by the regularly changing laser excitation power and measurement temperature following high-temperature annealing. After high-temperature annealing, the amorphous layer generated by arsenic ion implantation is transformed into a graphitization layer, resulting in a decrease in the NV yield. The electric neutral NV (NV0) center and negatively charged NV (NV−) center are affected by both radiation recombination and Auger recombination with increasing laser power. Accompanied by the increasing measurement temperature, the intensities of NV centers gradually decreased and eventually quenched. In addition, the charge states of NV− and NV0 centers were undergoing a transition. The zero phonon line positions of NV centers were also red shift, it was attributed to the dominant role of electron–phonon interaction in the temperature-dependent displacement of diamond energy gaps. The full width at half maxima of NV center were broadened significantly at higher temperatures. [ABSTRACT FROM AUTHOR]

Due to fascinating physical properties powered by remarkable progress in chemical vapor deposition of high-quality epilayers, diamond thin films attract great attention for fabrication of nitrogen-vacancy-based solid-state spin systems capable of operating in ambient conditions. To date, diamond heteroepitaxy via bias-enhanced nucleation is an unavoidable method for reliable wafer-scale film manufacturing. In this work, we analyze the coalescence phenomena in nitrogen doped, heteroepitaxial diamond epilayers, with a particular focus on their specific role in the annihilation of macroscopic crystal irregularities such as grain boundaries, non-oriented grains, and twinned segments. Here, we also report on the growth mechanism for the "primary" crystal orientation along with a predominant formation of two different types of boundaries highlighting the {011}-type as a main source of the crystal lattice irregularities. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate a hydrogen-terminated diamond (H-diamond) field-effect transistor (FET) with Al2O3/CeB6 gate materials. The CeB6 and Al2O3 films have been deposited by electron beam evaporation technique, sequentially. For the 4/8/12/15 μm gate length (LG) devices, the whole devices demonstrate distinct p-type normally off characteristics, and all the threshold voltage are negative; all the absolute values of leakage current density are 10−4 A/cm2 at a VGS of −11 V, exhibiting a relatively low leakage current density compared with CeB6 FETs, and this further demonstrates the feasibility of the introduction of Al2O3 to reduce the leakage current density; the maximum drain–source current density is −114.6, −96.0, −80.9, and −73.7 mA/mm, which may be benefited from the well-protected channel. For the 12 μm LG devices, the saturation carrier mobility is 593.6 cm2/V s, demonstrating a good channel transport characteristic. This work may provide a promising strategy for the application of normally off H-diamond FETs significantly. [ABSTRACT FROM AUTHOR]

Mn-doped diamond (111) layers were grown by microwave plasma chemical vapor deposition using bis(methylcyclopentadienyl)manganese as a Mn source. The Mn concentration ([Mn]) was intentionally controlled in the range between ∼1 × 1015 and ∼1 × 1017 cm−3 by regulating the Mn/C molar ratio in the gas phase within 0.15%–3.0%. When [Mn] > ∼1 × 1016 cm−3, the step edges of the growing surface changed from straight to a zigzag shape. Using a model based on the classic theory by Cabrera and Vermilyea, we show that this roughening of the step edges resulted from step pinning due to Mn atoms absorbed on the diamond surfaces. [ABSTRACT FROM AUTHOR]

We deduce equations to calculate coupling coefficients of diamond micro-ring resonators. The equations can be used universally at any wavelength but not limited to the transmission peaks/valleys, and can be adapted with triangular cross-sections and tapered waveguides. Consequently, we build three models in accordance to different diamond processing technologies. These models deal with ring resonators with either rectangular cross sections, or triangular cross sections, or with tapered bus for triangular cross sections. The calculated coupling coefficients can be well fitted by exponential decay functions of gap d. Due to geometrical limitations, triangular-cross-sectional diamond resonators are shown to have much smaller (factor 20) coupling coefficients than those of rectangular-cross-sectional resonators. A tapered bus is shown to be beneficial to increase the coupling coefficient. Besides the calculation of coupling coefficients, the method presented in the paper can also be used to calculate the bending loss of micro-ring resonators, as a complement to the existing methods. [ABSTRACT FROM AUTHOR]

This paper reports the energies and charge and spin distributions of the low-lying excited states in singlet and triplet N2V defects in diamond from direct Δ-SCF calculations based on Gaussian orbitals within the B3LYP, PBE0, and HSE06 functionals. They assign the observed absorption at 2.463 eV, first reported by Davies et al. [Proc. R. Soc. London 351, 245 (1976)], to the excitation of a N(sp3) lone-pair electron in the singlet and triplet states, respectively, with estimates of ∼1.1 eV for that of the unpaired electrons, C(sp3). In both cases, the excited states are predicted to be highly local and strongly excitonic with 81% of the C(sp3) and 87% of the N(sp3) excited charges localized at the three C atoms nearest neighbor (nn) to the excitation sites. Also reported are the higher excited gap states of both the N lone pair and C unpaired electron. Calculated excitation energies of the bonding sp3 hybrids of the C atoms nn to the four inner atoms are close to that of the bulk, which indicates that the N2V defect is largely a local defect. The present results are in broad agreement with those reported by Udvarhelyi et al. [Phys. Rev. B 96, 155211 (2017)] from plane wave HSE06 calculations, notably for the N lone pair excitation energy, for which both predict an energy of ∼2.7 eV but with a difference of ∼0.5 eV for the excitation of the unpaired electron. [ABSTRACT FROM AUTHOR]

Masers—the microwave analog of lasers—are coherent microwave sources that can act as oscillators or quantum-limited amplifiers. Masers have historically required high vacuum and cryogenic temperatures to operate, but recently, masers based on diamond have been demonstrated to operate at room temperature and pressure, opening a route to new applications as ultra-low noise microwave amplifiers. For these new applications to become feasible at a mass scale, it is important to optimize diamond masers by minimizing their size and maximizing the power of signals that can be amplified. Here, we develop and numerically solve an extended rate equation model to present a detailed phenomenology of masing dynamics and determine the optimal properties required for the copper cavity, dielectric resonator, and gain medium in order to develop portable maser devices. We conclude by suggesting how the material parameters of the diamond gain media and dielectric resonators used in diamond masers can be optimized, and how rate equation models could be further developed to incorporate the effects of temperature and nitrogen concentration on spin lifetimes. [ABSTRACT FROM AUTHOR]

Three sets of heteroepitaxial diamond crystals grown under nominally identical process conditions on Ir/YSZ/Si(001) substrates have been studied with respect to structural defects, chemical purity, and x-ray induced photoconductivity (PC). The dislocation density that varied systematically between 10 7 and 10 9 cm − 2 had a minor influence on dark conductivity and photoconductive gain G. In contrast, the substitutional nitrogen (N N ) and substitutional boron (N B ) defects, which are both present at very low concentrations (≤ 1 ppb), turned out to be the crucial factors controlling the electrical behavior. Small differences between both resulted in variations of the photocurrents by up to 5 orders of magnitude. The maximum in G of 0.75 × 10 4 was measured in the sample with highest dark conductivity. It could be explained conclusively within our model calculations on gain formation by N N ≤ N B . For low gain samples, we found N N > --> N B . However, the measured G values were far from theoretical predictions. This indicates a dominating role of additional traps. After x-ray switch-off, persistent photoconductivity (PPC) was observed in high gain samples. It was attributed to an energetic barrier hampering the recharging of nitrogen atoms by hole capture. As a possible source, strain fields generated by dislocations are suggested. [ABSTRACT FROM AUTHOR]

Detailed characterization of deep-level color centers requires understanding their electronic and atomic structure, which is most commonly investigated utilizing the Kohn–Sham density functional theory. Standard semilocal functionals based on the generalized gradient approximation (GGA) are inclined toward an imprecise quantitative description of defects' electronic structure. Hybrid functionals provide an improved prediction of electronic properties, albeit at a much higher computational cost. In this work, we test the newly developed Strongly Constrained and Appropriately Normed (SCAN) family of meta-GGA density functionals for selected color centers in diamond. In particular, we study nitrogen-, silicon-, germanium-, and tin-vacancy centers that have been recently investigated for their use in quantum technological applications. We show that SCAN and its derivatives, the rSCAN and r2SCAN functionals, significantly improve the calculated energies of optical transitions within the delta-self-consistent-field approach, almost reaching the accuracy of the hybrid Heyd–Scuseria–Ernzerhof (HSE) functional. In the case of the NV− center, we also show that the SCAN family of functionals improves the description of the adiabatic potential energy surfaces compared to both GGA and hybrid functionals, improving calculated luminescence lineshapes. As a result of these findings, we recommend using the SCAN family of functionals as a promising alternative for studying color centers in solids. [ABSTRACT FROM AUTHOR]

The advent of the new 5G communication standard has introduced demanding requirements for the performance of RF front-end filters, necessitating high frequency, large bandwidth, and other improved parameters. Consequently, researchers have been actively investigating the potential of surface acoustic wave resonators and film bulk acoustic resonators to address these needs, leading to the development of numerous novel structures. Through finite element simulation, a new heterogeneous stack structure Al/LN/diamond/Si with an interdigitated electrode resonant cavity is proposed. And the advantageous role of a diamond thin film in the surface acoustic wave resonant structure, including the excitation of high-frequency acoustic resonance modes and modulation of the electromechanical coupling coefficient has been studied. This structure holds promise for addressing the increasing demands for high-frequency, large-bandwidth RF front-end filters in the context of the new 5G communication standard. The results show that the central resonant frequency of the new structure resonator is 5284 MHz, the electromechanical coupling coefficient is 10.96%, and the Q factor value is 10 316, which has potential application value in the field of high-frequency filtering. [ABSTRACT FROM AUTHOR]

The properties of bulk contribution to sum-frequency generation reflected and transmitted by a finite layer in a multilayer system are described. The leading term is essentially due to the processes emitting in the transmission geometry, in particular for macroscopic layers. For such transmission processes, phase mismatch leads to the production of interference fringes when the layer thickness or a wavelength is tuned, which may be mistaken for resonant processes inside or at the surface of the material. Experimental evidence of such fringes measured from centrosymmetric bulks is provided for a diamond window in the far infrared and suggested for other materials in previously published data. The existence of a stationary point in the phase mismatch, related to the group velocity mismatch, is shown to be the source of another pseudo-resonant process in centrosymmetric calcium and barium fluorides, for which theoretical predictions reproduce the experimental observations. [ABSTRACT FROM AUTHOR]

We introduce and study the space of homeomorphisms of the circle (up to Möbius transformations), which are in |$\ell ^{2}$| with respect to modular coordinates called diamond shears along the edges of the Farey tessellation. Diamond shears are related combinatorially to shear coordinates and are also closely related to the |$\log \Lambda $| -lengths of decorated Teichmüller space introduced by Penner. We obtain sharp results comparing this new class to the Weil–Petersson class and Hölder classes of circle homeomorphisms. We also express the Weil–Petersson metric tensor and symplectic form in terms of infinitesimal shears and diamond shears. [ABSTRACT FROM AUTHOR]

The diagnostics of X‐ray beam properties has a critical importance at the European X‐ray Free‐Electron Laser facility. Besides existing diagnostic components, utilization of a diamond sensor was proposed to achieve radiation‐hard, non‐invasive beam position and pulse energy measurements for hard X‐rays. In particular, with very hard X‐rays, diamond‐based sensors become a useful complement to gas‐based devices which lose sensitivity due to significantly reduced gas cross‐sections. The measurements presented in this work were performed with diamond sensors consisting of an electronic‐grade single‐crystal chemical‐vapor‐deposition diamond with position‐sensitive resistive electrodes in a duo‐lateral configuration. The results show that the diamond sensor delivers pulse‐resolved X‐ray beam position data at 2.25 MHz with an uncertainty of less than 1% of the beam size. To our knowledge this is the first demonstration of pulse‐resolved position measurements at the MHz rate using a transmissive diamond sensor at a free‐electron laser facility. It can therefore be a valuable tool for X‐ray free‐electron lasers, especially for high‐repetition‐rate machines, enabling applications such as beam‐based alignment and intra‐pulse‐train position feedback. [ABSTRACT FROM AUTHOR]

During the diamond wire saw cutting process of sapphire crystals, warpage is one of the key parameters for evaluating wafer quality. Based on the thermoelasticity theory and diamond wire saw cutting theory, a finite element model for thermal analysis of diamond wire saw cutting sapphire crystals was established in this paper. The variation laws and internal connections of the temperature field and thermal deformation displacement field of the wafer during the sawing process were analyzed. A calculation and analysis model for the warpage of sapphire crystal wafer cut by wire saw was established based on the node thermal deformation displacement field of the wafer, and the rationality of the simulation results was verified through sawing experiments. This simulation calculation model constructs the mapping relationship between the process parameters of diamond wire sawing and the sapphire wafer warpage during sawing. The influence of wafer thickness, diamond wire speed, feed rate, diamond wire diameter, and tension on the warpage of the wafer was studied using the simulation model. The results indicate that the highest temperature occurs in the sawing area during cutting. The wafer thickness decreases and the warpage increases. The wafer warpage decreases with the increase of the diamond wire tension and diameter, and increases with the increase of diamond wire speed and feed rate. The research results provide a reference for understanding the variation of wafer warpage during sawing and optimizing sawing process parameters. [ABSTRACT FROM AUTHOR]

In this paper, we tackle the widely held view that practice-oriented approaches to ethics are conservative, preserving the moral status quo, and, in particular, that they do not promote any (fundamental) change in our dealings with animals or formulate clear principles that help us to achieve such change. We shall challenge this view with reference to Wittgensteinian ethics. As a first step, we show that moral thought and action rest on basic moral certainties like: equals are to be treated equally and unequals unequally. We then explore the relations between this insight and the notion of the difficulty of reality elaborated by Cora Diamond. Our goal is to show that a Wittgensteinian-Diamondian approach to animal ethics is not necessarily morally conservative. Indeed, it offers a profound practice-oriented approach to animal ethics that is capable of promoting change in human dealings with animals because it is compatible with radical critique. [ABSTRACT FROM AUTHOR]

By addressing the phenomenon of carbody abnormal vibrations in the field, the acceleration of the carbody and bogie was measured using accelerometers, and the diamond mode of the carbody was identified. The equivalent conicity of the wheelset and the acceleration at the frame end indicated that the shaking of the carbody was caused by bogie hunting. In the SIMPACK simulation, the acceleration frequency and amplitude at the frame end and midsection of the side beam were calculated. The lateral deformation amplitude of the side beam in the finite element model was extracted, and a modal shape function for the diamond-shaped mode was established. By utilizing the modal vibration equation, the modal generalized forces of the carbody were computed, revealing that, during carbody shaking, the yaw damper force contributed significantly among the forces of the secondary suspension, with the phase difference between the front and rear bogies approaching 180°. This insight offers a novel perspective for subsequent active control strategies. Subsequently, these modal generalized forces were applied as external excitation to a coupled vibration model encompassing both the carbody and transformer. Aiming to reduce the acceleration amplitude at the side beam, the transformer was treated as a dynamic vibration absorber, allowing for the optimization of its lateral suspension parameters. As a result, the lateral and vertical acceleration amplitudes at the side beam were concurrently reduced, with the maximum decrease reaching 58.5%, significantly enhancing the ride comfort. [ABSTRACT FROM AUTHOR]

Quantum state tomography (QST) of electron-nuclear spins of nitrogen-vacancy (NV) center in diamond commonly requires a sequence of population flipping operations and frequent calibration of basis states by fluorescence photon-counting. Here, we realize an effective and robust quantum state tomography of electron-nuclear spins based on time-resolved fluorescence, which can enhance the signal-to-noise ratio between different basis states up to 29.6% compared to the photon-counting method. Meanwhile, our method can directly obtain the population of four basis states with only one measurement, which significantly improves the efficiency of tomography. Furthermore, the photon count rate fluctuation of time-resolved fluorescence can be reduced to the standard quantum limit by normalization operation, indicating that the time-resolved method is calibration-free. This method could be easily applied to multi-nuclear spins of NV center in diamond and extended to other solid-state spin systems. [ABSTRACT FROM AUTHOR]

Since wound healing requires cells to repopulate a damaged area, cell migration is essential. In addition, migration plays a crucial role in cancer metastasis. Whether tumour cells can invade tissue and metastasize is a crucial factor determining their malignancy or in other words a hallmark of cancer (Lazebnik in Nat Rev Cancer 10: 232–233, 2010, https://doi.org/10.1038/nrc2827). Nanodiamonds potentially offer a powerful tool to investigate these migration processes. Due to their unprecedented photostability, they can function as long-term fluorescent labels. Besides, nanodiamonds are robust quantum sensors that can reveal, for instance, the temperature or the concentration of certain chemicals with nanoscale resolution. However, to utilise nanodiamonds to study cell migration, it is essential to understand if and how the presence of nanodiamonds influences cell migration. Here, we investigate this process for the first time. We found that nanodiamonds do not alter the speed at which HeLa cells populate a scratch at any tested concentrations. Furthermore, we tested cell attachment by quantifying focal adhesion points. Oxygen-terminated fluorescent nanodiamonds influence the cell spreading, the number of focal adhesions and the size of focal adhesion points. Interestingly, this is different for other types of nanodiamonds in the literature. For these particles, it has been described in the literature that they hinder cell migration. Our results support that fluorescent nanodiamonds do not influence cell migration strongly and thus can be used in labelling and sensing migrating cells. [ABSTRACT FROM AUTHOR]

The ordered mesostructures formed by block copolymers on the nanoscale via the self-assembly have attracted a lot of attention of high-performance material science due to its important, potential applications, especially the single gyroid network, single diamond network, and the single plumber′s nightmare (SPN) network. These three networks are very important in the fields of three-dimensional photonic crystals. Whereas single gyroid and single diamond have been stabilized in block copolymers by adjusting the chain architectures, blending, and using multicomponent systems, so far, no effective way has been found to stabilize the SPN network. Considering such situations, by designing B1A1B2A2C3B3, B1A1B2A2C3, B1A1C2B2A2C3, B1A1C2A2C3, and B1C1A1C2A2C3 multiblock copolymers and based on the simple cubic spheres to generate the unstable states via the rapid-component change of blocks, C, from B to A, the nonequilibrium kinetics of structural evolution starting from these unstable states and the corresponding mechanism as well as the effects from the number, position, and size of blocks, C, are explored. The exploration indicates that the metastable SPN network can be reached by the nonequilibrium kinetics of structural evolution after the rapid-component change of blocks, C, within a relatively wide range of volume-fraction A, which is mainly because that the symmetry of simple cubic spheres is the same as that of SPN (No.221 space group）. [ABSTRACT FROM AUTHOR]

Garnets are observed as phenocrysts in blocky rhyolites of Cumaovası Volcanites and are reddish-blackish in color, show vitreous luster, and have dodecahedron forms varying between 0.5 and 2.0 cm in size. In optical microscope investigations, they exhibit fractured structures and contain quartz, hematite, chlorite, and acicular rutile inclusions. Garnet phenocrysts are highly consistent with spessartine-type garnet end members in the Raman spectrum. This result is supported by the mineral chemistry results determined as spessartine (Sps)0.50–0.52 almandine (Alm)0.47–0.48 grossular (Grs)0.01–0.02. In the chondrite, primitive mantle, and Mid-Oceanic Ridge Basalt normalized multi element variation diagrams, garnet phenocrysts show enrichment in all elements (except Sr, K, P, and Ti). In contrast, in the upper continental crust normalized multi element variation diagram, garnet phenocrysts show depletion in large ion lithophile elements (Rb, Ba, K, and Sr) relative to high field strength elements. They exhibit slight enrichment in light rare earth elements ((La/Sm)N = 0.11–1.07) relative to heavy rare earth elements ((Sm/Yb)N=0.78–0.97). Furthermore, garnet phenocrysts have significant negative europium (Eu) ((Eu/Eu*)N = 0.01–0.02) and mildly positive cerium ((Ce/Ce*)N = 2.43–13.77) anomalies indicating hot and reduced magma conditions. The Y/Ho ratios have ranged from 18.9 to 20.3 and are close to the chondrite value. The zircon saturation temperatures (TZr) of the garnet's host rock was determined to be 756 °C. As a result of mineralogical, geochemical and gemological studies, it was concluded that Görece garnet phenocrysts have glassy luster and semi-transparent dodecahedral crystal shapes, so they can be classified as semi-precious gemstones. In addition, the rare earth element content of the garnet phenocrysts is similar to that of industrial garnet sands and it is thought that they may have potential. [ABSTRACT FROM AUTHOR]

Hardness is an important indicator of the wear resistance of tool materials. The study of the effect of hardness on the wear resistance of tool materials has significant practical applications. In this experimental work, a series of polycrystalline cubic boron nitride (PcBN) and diamond (PCD) compacts with different hardness are sintered under high temperature and pressure, and these samples were fashioned into turning tools, used for edge wear testing in the granite turning process. Based on the measurements above, the relationship between hardness and wear resistance in two materials with identical grain sizes (1–2 µm) was examined, and the results reveal a significant positive correlation between the hardness and wear resistance of the two materials. Remarkably, the relationship between hardness and wear resistance in two materials complies with the same type of fitting function. But incredibly, the wear resistance of the two materials exhibits inconsistency as the hardness increases. Specifically, below 40 GPa Vickers hardness, both materials exhibit comparable wear resistance. However, above 40 GPa, the difference in wear resistance between the two materials becomes more pronounced with increasing hardness. At the Vickers hardness of 70 GPa, the abrasion ratio of the PCD is approximately 3.5 times that of the PcBN, and it is anticipated that the disparity between them will continue to expand within the broader range of hardness. Further analysis reveals that the intrinsic hardness of the crystal grains significantly impacts the wear resistance of polycrystalline materials. [ABSTRACT FROM AUTHOR]

What sort of welfare regime does Brunei have? How does it compare to other countries' welfare schemes? How will it change as Brunei seeks to diversify away from its dependency on hydrocarbon resources? Using the "welfare diamond" framework, this article argues that Brunei currently operates a "protective welfare regime". However, if it succeeds in reducing its reliance on hydrocarbon resources, that system will transition towards a modern monarchical welfare-regime model wherein self-reliant individuals and resilient communities will play an increasingly significant role while the role of the state will diminish. [ABSTRACT FROM AUTHOR]

We numerically report highly efficient coupling of single photons from a single dipole source (SDS) using a pair of nanostructures. The maximum coupling efficiency ( η p ) of 56%, into guided modes of a silica nanotip (SNT), is found when the SNT of radius 0.43 μm is placed in the vicinity of a diamond nanotip (DNT) and a diamond nanowire (DNW). Additionally, we found that varying the radius of the DNT/DNW does not significantly affect the η p -value. Furthermore, we investigate the coupling efficiency (η ) of single photons from the SDS into guided modes of the DNT. The maximum η -value of 87% is found when the radially oriented SDS is positioned on the facet of the DNT of radius 0.4 μm. We found that the η p -value is enhanced when the DNT is placed in the vicinity of another DNT and the DNW. The present platform may open new possibilities in quantum networks. [ABSTRACT FROM AUTHOR]

The graphitization process of nano-crystalline diamond (NCD) under high pressure significantly influences the performance of sintered polycrystalline diamond bulks. Here, we investigated the graphitization temperature of both pure nano-diamond, with an average grain size of 50 nm, and a mixture of NaCl and nano-diamond powder in a pressure and temperature range of 5-9 GPa and 600-1 500 °C, respectively. With a quantitative analysis method employing powder X-ray diffraction, we analyzed the graphitization degree of NCD under different pressures and temperatures, examining both non-hydrostatic pressure conditions (pure NCD powder) and quasi-hydrostatic pressure conditions (NaCl-NCD mixed powder). Our findings indicate that the initial graphitization temperature of pure NCD powder exceeds 800 °C at 5 GPa, and ranges between 1 000 and 1 300 °C at 9 GPa. Notably, under quasi-hydrostatic pressure conditions at about 7 GPa, the graphitization temperature of NCD increases from 1 000 °C in non-hydrostatic pressure conditions to 1 500 °C or higher within a short holding time. [ABSTRACT FROM AUTHOR]

A representative amount of diamonds larger than 10.8 carats extracted from deposits of Yakutia during separate ore processing of each kimberlite pipe has been studied for the first time. It is shown that, according to the diamond typomorphic characteristics of habit, nitrogen content, and aggregation, as well as hydrogen concentration in diamond, it is possible to carry out a preliminary evaluation of the deposit to predict the presence of large and giant diamonds. It has been established that large diamonds from the deposits of the Daldyn-Alakitsky area have wide variations of nitrogen impurity and its aggregations in comparison with diamonds from the Malobotuobinsky and Srednemarkhinsky areas. It is determined that the content of large diamonds in the pipes of Yakutia is inversely proportional to the number of rounded dodecahedroids. The most promising deposits for finding large diamonds are those in which the majority of diamonds belong to one population—average nitrogen low-aggregated diamonds that were formed at a temperature of ~1100°C. According to the study of geological collections of diamonds, it is shown that, in kimberlite pipes with an increased nitrogen content in diamonds, an increase in the proportion of large diamonds in the deposit is noted. On the contrary, according to the aggregation of nitrogen in diamonds, as a parameter of postgrowth history, there is a negative correlation with the content of large diamonds. An increased value of the concentrations of hydrogen in diamonds not only negatively affect the total diamond content of the deposit, but also generally control the decrease in the content of large diamonds. [ABSTRACT FROM AUTHOR]

Diamond nanoparticles represent an elegant class of nanoscale materials with promising applications in nanotechnology. Solid-state NMR is a powerful technique for investigating the atomic-level structure and dynamics of nanomaterials in their natural state. The present study illustrates the application of high-resolution 13C NMR to nanomaterials characterization, and the fundamental 13C spin–lattice relaxation times highlight the spatial arrangement of surface-associated paramagnetic centers around the core sp3 carbon assembly of diamond nanoparticles, delineating the unique size-dependent physicochemical characteristics of diamond nanoparticles. [ABSTRACT FROM AUTHOR]

As the most prevalent element on our planet, carbon manifests a wide variety of allotropic phases, significantly contributing to its complex physical properties. Recently, several carbon allotropes have been reported to possess abundant topological phases in theory and experiment. This work focuses on a sp3 carbon allotrope, Z-ACA allotrope, which consists of 5-6-7-type Z-ACA carbon rings. This allotrope has been reported previously as a superhard material comparable to diamond. In this study, we report that it is a candidate for both an obstructed atomic insulator and a real Chern insulator. It is worth mentioning that Z-ACA exhibits an unconventional bulk-boundary correspondence due to its hinge boundary state manifestation. Our current research indicates that Z-ACA is a suitable carbon phase platform for studying the real topology and second-order bulk-boundary correspondence. [ABSTRACT FROM AUTHOR]

Nanomaterial phonon transport is crucial for miniaturized devices and superior thermophysical properties in condensed matter physics. Diamond nanosheets, applicable in nanoelectronics/optoelectronics, offer availability to explore dimensionality's impact on phonon transport. Raman spectroscopy is used to study the thermal conductivity (κ) of diamond nanosheets with a thickness below 100 nm. Results show a κ∼T−1$\kappa \sim {{T}^{ - 1}}$ law above 140 K, highlighting Umklapp phonon scattering. Despite the reduced thickness, κ (1100‐2000 W/mK) remains higher than metals and most semiconductors, showcasing diamonds' remarkable in‐plane heat transfer. Intriguingly, the research uncovers unique length‐dependent behavior κ∼log(L)$\kappa \sim {\mathrm{log}}( L )$, consistent with graphene, the two‐dimensional (2D) allotrope. This research offers insights into thermal transport in quasi‐2D nanosheets, with significant implications for nanoscale heat management and highly efficient thermal devices. [ABSTRACT FROM AUTHOR]

Diamond has the known highest thermal conductivity of around 2000 W m−1 K−1 and is, therefore, widely used for heat dissipation. In practical applications, synthetic diamond microparticles are usually assumed to have similar thermal conductivity to that of bulk diamond because the particle size is larger than the theoretical phonon mean free path, so that boundary scattering of heat-carrying phonons is absent. In this report, we find that the thermal conductivity of diamond microparticles anomalously depends on their sizes. The thermal conductivity of diamond microparticles increases from 400 to 2000 W m−1 K−1 with the size growing from 20 to 300 μm. We attribute the abnormally strong size effect to the long-range defects during the growth process based on analysis of point defects, dislocations, and thermal penetration depth dependence of thermal conductivity. Our results play a vital role in the design of diamond composites and in the improvement of the thermal conductivity of synthetic diamonds. [ABSTRACT FROM AUTHOR]

Pure single crystal diamond is a superior material for electronic, quantum, and detection applications. The state-of-the-art level of background concentrations of boron and nitrogen in such diamonds is about 1 ppb, which is quite close to the detection limit of the best chemical analysis techniques. In this work, we show that the boron concentration of ∼0.1 ppb causes conductivity of ∼5 kΩ cm of the single crystal diamond if the nitrogen concentration is lower. In such a case, the temperature dependent Hall effect measurement provides ∼100 times better detection limit for the concentration of the impurities in diamond compared to the conventional optical techniques. As a result, we have found the background concentrations of boron and nitrogen at the level of 0.07 and 0.02 ppb, respectively. This fact leads to a conclusion that growth of the insulating diamond is possible only when the nitrogen concentration is higher than the boron concentration. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate an ultrafast diamond Raman laser at 1240 nm with a pulse repetition rate of 956.62 MHz, a pulse duration of 39.5 ps, and an average power of up to 3.3 W based on synchronous pumping. The pump source is an electrical-pulse-modulated picosecond pulsed laser at 1064 nm with a repetition rate of 239.16 MHz and a pulse duration of 65.4 ps. A quadrupling repetition rate of the Raman pulse is achieved by synchronously amplifying both the forward and backward Raman pulses and the amplified Raman pulse undergoing two round trips in the resonator within one pump pulse period. The compression ratio of the pulse duration from the pump to the Raman is 1.66. This work offers a convenient and efficient method to significantly enhance the repetition rate of ultrafast crystalline Raman lasers and proves that a non-coherent ultrafast pump pulsed laser can be converted to a coherent mode-locked ultrafast Raman pulsed laser based on Raman conversion. [ABSTRACT FROM AUTHOR]

Diamond materials at different nanoscales provide them various characteristics such as elastic mechanical properties in needle‐like nanotips, flexibility of 2D films having atomic thicknesses and constant hardness under high pressures, superior field electron emission properties of vertically wall‐like composites, unprecedented hardness and improved toughness of nanotwin diamond (nt‐diamond), while the inherent excellent properties of bulk diamond (e.g., high Young's modulus, robustness, biocompatibility) can be maintained. In this paper, the newly born 1D diamond nanothreads, 2D diamanes, as well as 3D nt‐diamond are briefly reviewed. The innovations, progresses and achievements of different dimensional diamond nanostructures, covering lines, planes and volumes are overviewed. The topical problems and future outlooks of diamond nanostructures are outlined and discussed. [ABSTRACT FROM AUTHOR]

To reduce the matrix hardness of diamond composites for hard rock formations, Cu-based composites with lower sintering temperature and hardness were prepared by medium-frequency induction hot press sintering in this paper, with the addition of basalt fiber particles (BFPs) of 0 wt%, 1 wt%, 3 wt%, and 5 wt%. The microstructural characterization and property tests were carried out to research the effects of BFPs on the flexural strength, hardness, densification, and wear ratio of the composite. The result shows that when the BFPs addition was 1 wt%, the holding strength of the composites was increased by 10.3 % the hardness was increased by 5.9 % compared with the blank sample, and the diamond exposure became higher in the wear ratio test. The BFPs enhance the homogeneity of the composite structure, promote the diamond exposure in the composites, improve the holding strength of the composite of the diamond, and reduce the thermal damage of diamonds in the composites. [ABSTRACT FROM AUTHOR]

AbstractAnalytical solutions for the Boltzmann transport equation are typically limited to specific scenarios, prompting the research transport community to extensively explore numerical approaches with special attention to the discrete ordinates (SN) formulation. The spectral nodal methods are widely recognized for their capability to preserve the analytical solution of the SN mathematical model. However, these formulations exhibit notable complexity with high-order polynomial approximations for the transverse leakage terms, motivating researchers to pursue simpler hybrid approaches by partially preserving the analytical solution. Both spectral nodal and hybrid spectral nodal methods introduce nonstandard auxiliary equations not amenable to standard iterative schemes due to a highly coupling in angular directions. Following these ideas, we present a finite element – spectral nodal hybrid method referred to as Extended Diamond Difference-Constant Nodal (EDD-CN) method for two-dimensional fixed-source discrete ordinate transport problems with constant nodal approximation for the leakage terms. The proposed method seeks to preserve eigenfunctions associated with the dominant pair of eigenvalues in the transverse integrated SN equations. In addition, we propose a novel iterative scheme called Decoupled Cell Iteration (DCI) scheme which decouples the angular directions in the nonstandard auxiliary equations and follows conventional iteration transport sweeps for solving SN problems. [ABSTRACT FROM AUTHOR]

The interest in microdosimetry is growing thanks to the advancement in microdosimetric technologies, improving detector performance and reliability. Herein, the fabrication and characterization of a novel diamond‐based microdosimeter are proposed. The microdosimeter consists of an array of single‐crystal diamond Schottky diodes about 1.5 μm thick connected in parallel. The detector prototypes are characterized using the ion beam‐induced charge technique, employing a 6 MeV carbon ions microbeam. Despite a good overall response, the first prototypes are affected by the "bridge effect": a charge collection beneath the metallic bridges connecting the sensitive volumes (SVs), which alters the energy deposition spectrum. To mitigate the bridge effect, different technological solutions are explored: the selective growth of intrinsic diamond layers and the use of an insulating material such as photoresist. These second prototypes reveal a good SV spatial definition without any charge collection from the bridges and a good response homogeneity within the SVs ranging between 3% and 5% full‐width‐half‐maximum among the different prototypes. While the cell‐like thickness and lateral dimensions of SVs make the diamond microdosimeter array ideal for radiobiological applications, its array configuration can make it highly versatile to perform under different fluence rate conditions in particle therapy. [ABSTRACT FROM AUTHOR]

To preserve the structural and interfacial integrity of diamond, diamond/SiC composites were fabricated by Si infiltration under gas flow guidance. The characteristics of these materials are significantly affected by the interfacial reaction between Si and diamond. The interface formation was studied extensively by locally analyzing the microstructure of the interfacial regions via transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and X-ray diffraction (XRD). The results demonstrated that the extent of reactive erosion of diamond by Si weakened as the gas velocity increased during the infiltration process. Nanocrystalline Si 5 C 3 and β-SiC grains with an orientation relationship were observed at the diamond/SiC interface. Furthermore, by employing gas flow guidance, the diamond/SiC composites exhibited a better specific stiffness, measuring up to 183.3 × 106 m2 s−2, which represents an exceptional 18 % improvement compared with the control group. [ABSTRACT FROM AUTHOR]

Diamond/SiC composites offer valuable applications in thermal management because of their exceptional thermal properties. Currently, the predominant method employed for crafting diamond/SiC composites is the reaction sintering approach. However, it encounters the challenge of a high residual silicon content. In this study, we introduced techniques such as bimodal diamond particles and high-density carbon sources (submicron diamond powder) to enhance the diamond content and reduce the residual silicon, optimizing the phase composition. The results indicated the diamond/SiC composite demonstrated a thermal conductivity of 666 W/m·K, a thermal expansion coefficient of 2.73 × 10−6 K−1, and an elastic modulus of 753 GPa. Furthermore, the meticulous assessment of the interface microstructure of diamonds in the diamond/SiC composite was conducted using transmission electron microscopy. The formation of nanocrystal-SiC and interface defects were elucidated by the mechanism of carbon dissolution saturation. [ABSTRACT FROM AUTHOR]

Introduction: In this study, we developed an integrated situational taxonomy by merging the second-generation situational taxonomies of the DIAMONDS and CAPTION models. Method: The study participants included 363 adults aged 25-39 years, residing in South Korea, with at least a college degree, and currently employed. To integrate the factors of both models, we conducted an exploratory factor analysis and further examined the hierarchical structure of these factors using bass-ackwards analysis. Results: Our analysis revealed that the integrated situational taxonomy comprises seven domains with a confirmed hierarchical structure. Building on these findings, we further conducted a comparative analysis of the results with prior situational taxonomy research. Discussion: It was found that the factors constituting integrated domains derived from previous studies that employed correlation analysis or factor analysis differed from those of our study. However, the taxonomy of the three domains in the third level (negativity, positivity, and tasks) aligned with that of previous relevant research, suggesting that these domains are universally applicable to situational taxonomy. Hence, although the taxonomy of the three domains does not encapsulate specific situational characteristics, like the seven domains, if one seeks a culturally universal, statistically clear, and concise structure of situational taxonomy, the three-domain one is a promising alternative to the seven domains. Moreover, this study is the first situational taxonomic research outside the United States and European cultural spheres that confirms that an integrated situational taxonomy is similarly applicable in East Asian cultures. [ABSTRACT FROM AUTHOR]

The growth of chemical vapor deposition diamond in microwave plasma ignited in H2/CH4 gas mixture is investigated using a multiscale approach. The plasma composition and temperatures are determined as a function of the growth conditions using an axial one‐dimensional simulator. The growth process is then studied at the atomic scale using a kinetic Monte‐Carlo simulator developed for (1 0 0), (1 1 1), and (1 1 0) orientations. The calculated growth rates are then injected in a geometric model that predicts the final morphology of the crystal. The simulation of the growth on an etch pit shows that the time necessary to entirely fill the pit is around half an hour. The study of the growth on the three orientations reveals that the surface temperature and methane concentration influence the number, shape, and size of the islands when they appear. On the (1 0 0) surface, the formation of islands may be related to Stranski–Krastanov growth mode, whereas the (1 1 1) surface conducts to Frank–van der Merwe growth mode, and the (1 1 0) surface is governed by Volmer–Weber growth mode. [ABSTRACT FROM AUTHOR]

This paper is devoted to studying some new reverse Hölder-type inequalities associated with the dynamic integral called diamond on time scale, which is expressed as an ’approximate’ symmetric integral on time scales. Some related inequalities are also presented. The obtained inequalities extend known results related with discrete and continuous forms. [ABSTRACT FROM AUTHOR]

The low‐concentration boron doping is performed from 1016 to 1018 cm−3 by ion implantation into heteroepitaxially synthesized large‐area diamond and electrical properties are investigated. Photoluminescence analysis is first carried out to clarify the optical properties of the heteroepitaxial diamond substrate. As a result, defect complexes of nitrogen‐vacancy and silicon‐vacancy are hardly detected in this substrate, suggesting that optically high‐purity diamond can be accomplished by heteroepitaxial growth. Then, the electrical properties of resistivity, mobility, carrier concentration, and conductive type by Hall effect measurements are investigated. For the samples with doping concentrations higher than 1016 cm−3, the electrical activation of implanted B acting as acceptors is confirmed. The compensation ratio for the sample with 3.5 × 1017 cm−3 concentration reaches 76%, indicating the presence of compensating donor‐like centers. With increasing the doping concentration to 3.5 × 1018 cm−3, the compensation ratio is significantly reduced to 35%. The observed mobility of the higher doped sample takes almost the ideal value observed for the sample doped by chemical vapor deposition process. It is suggested that the heteroepitaxial synthesis of large‐area and high‐purity substrates should contribute to the further development of the application to electronic, optical, and sensing devices in the future. [ABSTRACT FROM AUTHOR]

Two pear-shaped old-cut diamonds (7.79 and 5.90 ct) of dark greenish brownish grey and dark greenish grey colour, respectively, were submitted to LFG for grading. Both were found to be type IIb diamonds containing about 0.1 ppm uncompensated boron (as calculated from FTIR spectra). The two diamonds presented similar spectroscopic and structural features, and they were most likely cut from the same rough. We offer two hypotheses for the relative positions of the stones and the potential shape of the rough. [ABSTRACT FROM AUTHOR]

Extremely reliable and wear‐resistant components are required for subsea pump applications. For this purpose, materials and components were developed and qualified within the framework of a joint project1, which under media lubrication with water containing particles, exhibit the highest possible wear resistance and can thus achieve the longest possible service life. The developed SiC‐bonded diamond ceramics have diamond contents of up to 60 % by volume and can be manufactured in the form of a solid material or as graded components containing diamonds only in the tribologically stressed areas. The results show that the investigated diamond‐containing ceramics are very suitable for media‐lubricated sliding bearings and mechanical seals in subsea applications. The friction values under media lubrication are very stable and independent of tribological loads. In mechanical seal application, SiC‐bonded diamond shows significantly better friction performance than the reference material SiC. An outlook is given on demonstrator tests that are currently in preparation. [ABSTRACT FROM AUTHOR]

Beamline B21 at the Diamond Light Source synchrotron in the UK is a small‐angle X‐ray scattering (SAXS) beamline that specializes in high‐throughput measurements via automated sample delivery systems. A system has been developed whereby a sample can be illuminated by a focused beam of light coincident with the X‐ray beam. The system is compatible with the highly automated sample delivery system at the beamline and allows a beamline user to select a light source from a broad range of wavelengths across the UV and visible spectrum and to control the timing and duration of the light pulse with respect to the X‐ray exposure of the SAXS measurement. The intensity of the light source has been characterized across the wavelength range enabling experiments where a quantitative measure of dose is important. Finally, the utility of the system is demonstrated via measurement of several light‐responsive samples. [ABSTRACT FROM AUTHOR]

Diamond nanoparticles/urethane-based bio-adhesives (ND-U-BA) were synthesized via in-situ polymerization. Chemical structure and curing kinetics of the samples were studied by Fourier-transform infrared spectroscopy. Results showed NDs controlled the curing profile of samples. Thermal and crystalline properties were studied using differential scanning calorimetry and X-ray diffraction analyses. Results indicated hard segments had higher ordering levels in the presence of NDs which is due to the lower hydrogen bonding among polyurethane chains. Mechanical results showed ND-U-BA had higher adhesion strength due to the formation of chemical crosslinks and a controlled curing mechanism. MTT and biodegradation studies showed ND-U-BA had acceptable cell viability and degradation content. • Urethane and diamond nanoparticles/urethane-based bio-adhesives were synthesized. • Results showed ND nanoparticles had controlling effect on curing kinetic of samples. • Cell viability of bio-adhesives was improved with the ND nanoparticles' addition. • Incorporation of ND nanoparticles increased the adhesion strength of bio-adhesive. [ABSTRACT FROM AUTHOR]