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Diamond-like Carbon (DLC) has been used as a coating material of choice for a variety of technological applications owing to its favorable bio-tribo-thermo-mechanical characteristics. Here, the possibility of bringing DLC into orthopedic joint implants is examined. With ever increasing number of patients suffering from osteoarthritis as well as with the ingress of the osteoarthritic joints malaise into younger and more active demographics, there is a pressing need to augment the performance and integrity of conventional total joint replacements (TJRs). Contemporary joint replacement devices use metal-on-polymer articulations to restore function to worn, damaged or diseased cartilage. The wear of polymeric components has been addressed using crosslinking and antioxidants; however, in the context of the metallic components, complications pertaining to corrosion and metal ion release inside the body still persist. Through this review article, we explore the use of DLC coatings on metallic bearing surfaces and elucidate why this technology might be a viable solution for ongoing electrochemical challenges in orthopedics. The different characteristics of DLC coatings and their feasibility in TJRs are examined through assessment of tribo-material characterization methods. A holistic characterization of the coating-substrate interface and the wear performance of such systems are discussed. As with all biomaterials used in TJRs, we need mindful consideration of potential in-vivo challenges. We present a few caveats for DLC coatings including delamination, hydrophobicity, and other conflicting as well as outdating findings in the literature. We recommend prudently exploring DLC films as potential coatings on metallic TJR components to solve the problems pertaining to wear, metal ion release, and corrosion. Ultimately, we advise bringing DLC into clinical use only after addressing all challenges and concerns outlined in this article.

Boron nitride has attracted scientific interest in recent years due to its potential use in electronics, both as hexagonal (hBN) and cubic (cBN) phases. While both are successfully realized through chemical vapor deposition, the heteroepitaxial growth of cBN on another iconic semiconductor, diamond is plagued with mixed‐phase formation. Employing first‐principles computations and a nanoreactor approach, the BN phase preferences are explored on diamond (001) controlled—as it is discovered—by the hydrogen gas concentration. In a limited‐hydrogen environment, the initial BN‐island expands along the diamond surface, forming a 3D metastable cubic phase that grows in the direction normal to the basal plane through kinetically‐limited nucleation, thus overcoming the thermodynamic preference toward the hBN phase. Comparatively, the amorphous phase is favored in the absence of hydrogen, while the hexagonal phase dominates at its high levels, elucidating numerous experimental observations. A obtained kinetic phase diagram connects the phase with hydrogen chemical potential to facilitate targeted phase selection. The results suggest that gas‐mediated nucleation kinetics provide feasible control for the precise synthesis. It also offers valuable guidance for the controllable synthesis of desired BN phases and advances research toward potential BN electronics. [ABSTRACT FROM AUTHOR]

Ion implantation in diamond crystals is widely used both for producing conducting microstructures in the bulk of the material and for creating isolated photon emitters in quantum optics, photonics, cryptography, and biosensorics. The photoluminescence (PL) spectra of helium ion-implanted diamonds are dominated by two sharp emission lines, HR1 and HR2 (from Helium-Related), at ~536 and 560 nm. Here, we report on PL studies of helium-related optical centers in diamonds. Experiments have been carried out on a (110) plate of natural single-crystal type IIa diamonds. The uniform distribution of radiation defects in a 700 nm-thick layer was obtained by ten cycles of multiple-energy (from 24 to 350 kV) helium ion implantation with a total dose of 5 × 1016 cm−2. The diamonds were annealed in steps in a vacuum oven at temperatures from 200 to 1040 °C. It is demonstrated that helium ion implantation in diamonds followed by annealing gives rise to more than a dozen various centers that are observed in the PL spectra in the range of 530–630 nm. The transformations of the PL spectra due to annealing are investigated in detail. The spectral shapes of phonon sidebands are determined for the HR1, HR2, and HR3 bands with ZPLs at ~536, 560, and 577 nm, respectively, and it is shown that these bands are attributed to interstitial-related centers in diamonds. The reported results are important for understanding the structure and properties of helium-related defects in diamonds. [ABSTRACT FROM AUTHOR]

Diamond containing nitrogen‐vacancy centers (NV−) is one of the most investigated materials for quantum technologies, because of this system's exceptional spin properties. Although the NV− optical transition is very bright, it suffers from spectral diffusion and weak zero‐phonon line, and is in the visible range. This limits integration into quantum photonic structures and interfacing with optical fiber networks. In contrast, rare earth (RE) ions exhibit extremely narrow and stable optical transitions, including erbium's 1.5 µm telecom wavelength. Combining RE with NV− properties through short‐range interactions is however challenging as RE do not readily enter the diamond lattice. In this work, a thin‐film‐based architecture in which RE and NV− centers can interact while preserving their unique properties is introduced. Thin films of Er3+:Y2O3 are grown by chemical vapor deposition on diamond substrates with well‐crystallized and highly textured structures. An extensive spectroscopic study of Er3+ transitions at room and low temperatures further reveals that photoluminescence spectra and decays are close to bulk materials. It is also shown that Y2O3 thin film deposition has no detrimental effects on NV− optical and spin properties. RE thin films deposited on diamond can thus be suitable for building hybrid materials for new functionalities in quantum sensing, communication, and processing. [ABSTRACT FROM AUTHOR]

Although poly-ether-ether-ketone (PEEK) implants hold significant medical promise, their bioinert nature presents challenges in osseointegration and bone ingrowth within clinical contexts. To mitigate these challenges, the present study introduces Diamond PEEK/bioactive glass (BG) composite scaffolds, characterized by macro/micro dual-porous structures, precisely fabricated via laser powder bed fusion (LPBF) technology. The findings indicate that an increase in BG content within these scaffolds significantly augments their hydrophilicity and hydroxyapatite formation capacities. Stress-strain curve analysis demonstrates reliable load-bearing stability across all scaffold types. In vitro assessments confirmed the non-cytotoxicity of PEEK/BG samples and demonstrated improved osteogenic differentiation and mineralization with increased BG incorporation. Further, in vivo experiments illustrated that the Diamond porous structure of these scaffolds facilitated bone growth, an effect notably amplified with higher BG content. Particularly in groups with 15 wt.% and 25 wt.% BG scaffolds, new bone formation was observed not only within the macropores of the Diamond structure but also within the micropores inside the scaffold rod, suggesting an almost seamless fusion with the new bone. This demonstrates the scaffolds' effective osteointegration and bone ingrowth properties. This study conclusively established the effectiveness of Diamond-structured PEEK/BG composite scaffolds, fabricated via LPBF, in bone repair. It highlights the crucial role of BG in enhancing osteogenic potential through interaction with the macro/micro pores of the scaffold. This study addresses the bioinert nature of PEEK implants by developing Diamond-structured PEEK/bioactive glass (BG) composite scaffolds by laser powder bed fusion. The dual-porous macro/microstructure enhances hydrophilicity and hydroxyapatite formation, vital for bone regeneration. By adjusting the BG content, we controlled the melt viscosity and sintering rate, leading to the formation of beneficial microscale pores. These pores resolve the issue of ineffective bioactive fillers in previous LPBF-fabricated scaffolds, enhancing the osteogenic potential of BG and inducing superior bone ingrowth and osseointegration. In vitro and in vivo analyses show enhanced osteogenic differentiation, mineralization, and bone growth, underscoring the clinical potential of these scaffolds for bone repair. [Display omitted] [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]

Overcoming the hardness‐toughness trade‐off in diamonds attracts much interest in physics, chemistry, materials science, and engineering. Recently synthesized nanotwinned diamond composite exhibits massive enhancement in fracture toughness without sacrificing its unprecedented Vickers hardness [Y. Yue et al., Nature 582, 370 (2020)]. Several mechanisms for the toughness enhancement are unveiled based on the edge‐cracked models while the mechanism from Vickers indentation has remained elusive. Here, the energy of nanotwinned diamonds, diamond polytypes, and diamond composites is systematically investigated from Vickers indentation simulation. The results show diamond structures dissipate energy by interface migration, accompanied by the phase transformation from diamond polytypes to the cubic diamond (3C diamond). By tuning the density and distribution of interfaces, the dissipated energy of the diamond is increased to more than twice that of a single‐crystal 3C diamond. This work complements the established mechanisms and provides a universal strategy for toughening diamonds and related materials. [ABSTRACT FROM AUTHOR]

The increasing demand for chip heat dissipation has led to more challenges in designing and regulating thermal interface materials with high performance. It is crucial to have a comprehensive understanding of the design and mechanism of thermal conduction path built by thermal conductive fillers. Diamond, in particular, has garnered significant attention. In this study, we constructed three-dimensional particle random distribution models of diamond/silicone rubber composites based on the morphological characteristics of common industrial-grade diamond. We also conducted experiments with different morphologies and filling amounts of diamonds in silicone rubber to better understand the effect of diamond fillers on the thermal conductivity of the composites. From the model simulation, thermal conductivity and actual LED temperature rise tests, the study reveals that broken single-crystal diamond with lamellae or rod-like with large aspect ratio or radius-thickness ratio is easier to form thermal transfer paths than spherical or spherical-like diamond under low filling content. Ultimately, the silicone rubber composites filled with intact hexa-octahedral single-crystal diamonds achieve the highest thermal conductivity as a result of the formation of more comprehensive three-dimensional heat dissipation network (1.357 W/(m K), 80 wt.%). In comparison with silicone rubber composites filled with spherical Al2O3 (0.995 W/(m K), 80wt.%) and pure silicone rubber (0.21 W/(m K), 80 wt.%), the thermal conductivity increases by 36% and 546%, respectively. The revelation of the construction law and mechanism of different diamond morphologies on the thermal conduction path of thermal interface materials provides a theoretical basis for broadening the application of diamond in the design of thermal interface materials. [ABSTRACT FROM AUTHOR]

Diamond is a material with promising electronics applications but with challenges in effective doping. Cubic boron nitride (cBN), due to its similar lattice structure, is ideal for forming heterostructures with diamond, to modify electronic properties and especially shift the band positions. Here it is demonstrated how integrating cBN layers of finite thickness in diamond can induce an electronic band offset near the polarized diamond‐cBN interface. Beyond the direct density functional theory computations, an analytical model is developed for rapid examination of the band offset, for a broad number of crystallographic orientations, in excellent agreement with ab initio calculations. Results show that near [100] and [111] crystal directions, the diamond|cBN|diamond heterostructure displays a 3–4 eV band offset which is expected to facilitate effective modulation doping of diamond. [ABSTRACT FROM AUTHOR]

Metallization of diamond with transition metals (TMs) has attracted much attention as they play an important role in the development of precision machining, high‐end thermal management, especially for electronic devices. However, it is found that the solid‐state reaction does not stop at the interface, potentially hampering interface engineering. To unleash the full potential of diamond devices, deeper reactions are investigated in monocrystalline intrinsic diamond metallized with Ti/Pt/Au ohmic contacts combing experiments and theoretical calculations. Apart from exhibiting TiC, graphite, TMs, and diamond nanocrystallites at the interface, a unique ion‐implanted‐like multilayered structure is observed at micrometer depth. TM atoms penetrate through diamond produce a buried amorphous carbon layer under the damaged diamond lattice. In addition, these theoretical calculations reveal that the structural amorphization is catalyzed by the incorporation of TM atoms through vacancy‐mediated diffusion, which induces the closure of the bandgap of the diamond. This facilitates carriers crossing the bandgap via impurity band conduction and promotes the formation of the ohmic contact. This study provides critical insight into the microscopic mechanisms of the metallization between diamonds and TMs and could facilitate the development of diamond‐based electronic devices with a tailored electronic property. [ABSTRACT FROM AUTHOR]

In this work, we actively investigated a betavoltaic cell model that demonstrated high accuracy and reproducibility, utilizing both Monte Carlo (MC) simulations and Technology Computer-Aided Design (TCAD) for its development. This model integrates diamond-based metal/intrinsic/p-doped (MIP) Schottky diode structures and employs the following commonly utilized radioactive isotopes: 63Ni, 147Pm, 14C, and 3H. The optimal response of the MIP structure devices to these four radiation sources has been refined through computational modeling. To achieve optimal efficiency from betavoltaic cells when exposed to various radiation sources, design parameters were obtained, a 9 µm thick i-layer with a doping concentration of 1E14 cm− 3 under 2 µm of 63Ni, yielding an efficiency of 10.7%; a 40 µm thick i-layer with a doping concentration of 1E10 cm− 3 under 30 µm of 147Pm, resulting in an efficiency of 7.58%; a 30 µm thick i-layer with a doping concentration of 1E12 cm− 3 under 70 µm of 14C, achieving an efficiency of 9.6%; a 3 µm thick i-layer with a doping concentration of 1E15 cm− 3 under 1 µm of 3H with the lowest energy, which can obtain an efficiency of up to 30.7%. Due to the high energy density of 147Pm, it can theoretically achieve a power density of 63 µW·cm− 2. Ultimately, we propose the design of a one-third optimization strategy for high-performance diamond MIP Schottky betavoltaic cells. [ABSTRACT FROM AUTHOR]

Diamond plays a significant role in the fields of mechanics, optics, thermology and electronics (such as semiconductors) with its excellent properties. However, the surface quality of diamond affects its application in these areas. Therefore, obtaining high-quality surfaces through efficient polishing technology has always been a focus of diamond research. The main diamond polishing technologies include mechanical polishing, thermochemical polishing, laser polishing and chemical mechanical polishing, among which chemical mechanical polishing (CMP) has the advantages of low equipment operating costs, simple process, and minimal surface damage after polishing. Based on the analysis and comparison of the above polishing methods, this paper focuses on the field of CMP and makes a detailed comparison and analysis of its development history. Although the early CMP technology had certain limitations in process and polishing efficiency, it lays the foundation for the innovation and optimization of the subsequent technology; the application of H2 O2 and its mixtures not only enhances the chemical reaction activity in the process of CMP and improves the material removal rate, but also effectively reduces the surface roughness and improves the surface quality of diamond; the photocatalytic assisted chemical mechanical polishing can enable diamond to achieve a high surface quality, but the equipment is relatively complicated and cannot meet the demand of mass production, which needs further research and optimization. In addition, this paper also predicts the future development of chemical mechanical polishing to provide reference for researchers in related fields. [ABSTRACT FROM AUTHOR]

This article describes a novel dataset on non‐diamondiferous eclogite and garnet pyroxenite xenoliths from four kimberlite pipes of the Ekati Diamond Mine (Central Slave Craton, Canada). Xenoliths brought to the surface by kimberlite eruptions are direct sources of information on the composition and evolution of the Earth's mantle. Eclogite and garnet pyroxenite xenoliths, specifically, are testimony of subduction into, and metasomatism of, the mantle beneath cratons. Furthermore, these rocks are major hosts for diamond and thus an important part of the deep carbon cycle. The sample suite consists of 41 small xenoliths (2–5 cm) recovered from drill cores. The dataset includes major and trace element concentrations for garnet, clinopyroxene and ilmenite, as well as stable oxygen isotope compositions of garnets. Strontium and neodymium isotopic compositions are reported for garnet and clinopyroxene for four samples which were large enough to allow for analysis. Overall, this dataset significantly expands and complements existing datasets on diamondiferous and non‐diamondiferous xenoliths from the Slave Craton in Canada, furthering our understanding of the composition of the Slave subcratonic lithosphere. The dataset includes several samples with rare mineral assemblages, including an olivine‐bearing eclogite as well as ilmenite and apatite‐bearing garnet‐pyroxenites, and thus provides data shedding light on rarely reported compositional nuances in xenolith suites found in kimberlites. [ABSTRACT FROM AUTHOR]

This work report the generation of high‐order Laguerre–Gaussian (LG) modes from a nanosecond, optical vortex pumped diamond Raman laser. This system is capable of generating first‐Stokes (λ1st = 1240 nm) LG modes with topological charge (ℓ) of up to 26 and second‐Stokes (λ2nd = 1485 nm) LG modes with topological charge of up to 22, when pumped using a first‐order vortex beam. The maximum first‐ and second‐Stokes LG mode energies are measured to be 0.5 and 1 mJ, respectively, when pumping with energy of 19.8 mJ. [ABSTRACT FROM AUTHOR]

RBSC with a low residual Si less than 5 vol% was fabricated using SiC–C preform with diamond as a main carbon source by a conventional reaction sintering process at the temperature range between 1500 °C and 1800 °C. The diamond content in the SiC–C preform varied from 10 wt% to 17 wt%. The diamond as the main carbon source used in SiC–C preform effectively minimized the residual Si in RBSC by increasing the reaction of diamond due to the enhanced Si melt infiltration even in SiC–C preform with high carbon content. The Si melt infiltration should be performed above 1600 °C for the complete reaction of diamond particles with size of 0.5 μm because of the relatively low dissolution rate of diamond in Si melt. The flexural strength of RBSC with residual Si content less than 7 vol% exceeded 400 MPa. The flexural strength of RBSC was increased with decreasing residual Si content, but sharply decreased by the residual carbon accompanying pores in RBSC. RBSC with low residual Si content displayed moderate flexural strengths around 200 MPa even above Si melt temperature because of the formation of continuous SiC structure in RBSC by the enhanced grain growth of SiC. Vickers hardness of RBSC was steadily increased from 17.7 GPa to 24.6 GPa with decreasing residual Si. [ABSTRACT FROM AUTHOR]

Diamond is renowned as the ultimate semiconductor thanks to its exceptional physical properties, including unmatched hardness, exceptional wear resistance, superior mechanical and tribological characteristics, and high fracture strength. Diamond solution-gate field-effect transistors (D-SGFETs) leverage these advantages, along with their outstanding high-power and high-frequency performance, excellent thermal conductivity, wide bandgap, high carrier mobility, and rapid saturation speed. These features make D-SGFETs highly promising for fast and precise biomedical detection applications. This paper provides a comprehensive review of the fabrication techniques for diamond SGFETs, encompassing diamond film synthesis, surface conduction layer formation, source/drain fabrication, and FET packaging. Furthermore, the study delves into the surface functionalization of diamond SGFETs and their diverse applications in biomedical detection. Finally, the paper discusses the future outlook of diamond SGFETs in advancing biomedical detection technologies. [ABSTRACT FROM AUTHOR]

Micrometer-sized diamonds were incorporated into silicon nitride (Si3N4) matrix to manufacture high-performance Si3N4-based composites using spark plasma sintering at 1 500 °C under 50 MPa. The effects of the diamond content on the phase composition, microstructure, mechanical properties and thermal conductivity of the composites were investigated. The results showed that the addition of diamond could effectively improve the hardness of the material. The thermal conductivity of Si3N4 increased to 52.97 W/m·k at the maximum with the addition of 15 wt% diamond, which was 27.5% higher than that of the monolithic Si3N4. At this point, the fracture toughness was 7.54 MPa·m1/2. Due to the addition of diamond, the composite material generated a new substance, MgSiN2, which effectively combined Si3N4 with diamond. MgSiN2 might improve the hardness and thermal conductivity of the materials. [ABSTRACT FROM AUTHOR]

Polycrystalline diamond (PCD) is widely used for micro tools due to its high hardness and wear resistance. However, micro PCD tools face challenges in machining with high accuracy and efficiency. Therefore, electrical discharge machining grinding (EDM-grinding) composite machining was proposed. The effects of pulse discharge parameters on surface quality and microhole drilling performance of PCD tool were investigated. The results show that the surface roughness of helix flute and flank face of the fabricated PCD tool were 0.125 µm and 0.158 µm, respectively, as well as the inner wall roughness achieved 0.331 µm after drilling of microhole. The average current displayed a greater effect on the machining quality of PCD tools, with tool breakage in excessive average current. The preferred pulse discharge parameters were determined as an open-circuit voltage of 95 V, an average current of 1400 mA, a pulse width of 400 ns, and a pulse interval of 2000 ns. [ABSTRACT FROM AUTHOR]

Key implementation points for achieving full accuracy in simultaneous temperature and magnetic field measurement and linearity when applying diamond quantum sensors to electric vehicle (EV) battery monitors were investigated. Both the static and busbar current magnetic field are required to be aligned to the NV-axis. If misalignment should exist, the resonance frequency midpoint move in the direction opposite to the temperature change under a large busbar current due to the transverse magnetic field effect. Misalignment could be quantified with an accuracy of ±1° by analysing the resonance frequency midpoint change under a current of ±1,000 A. The transverse magnetic field effects compensation estimated from misalignment, confirmed that the resonance frequency midpoint changed consistently with temperature changes. Furthermore, linearity over a wide dynamic range also improved. Moreover, it will contribute to accurate alignment of the two sensors for differential detection to eliminate external noise as common mode. These are expected to expand the application of diamond sensors for high-precision measurement in a wide dynamic range. [ABSTRACT FROM AUTHOR]

Understanding the microscopic thermal effects of the hydrogel is important for its application in diverse fields, including thermal‐related studies in tissue engineering and thermal management for flexible electronic devices. In recent decades, localized thermal properties, such as thermal conductivity, have often been overlooked due to technical limitations. To tackle this, the study proposes a new hybrid diamond microsensor that is capable of simultaneous temperature control and readout in a decoupled manner. Specifically, the sensor consists of a silicon pillar (heater) at ≈10 microns in length, topped by a micron‐sized diamond particle that contains silicon‐vacancy (SiV) centers (thermometer) with 1.29 KHz−12${\mathrm{K}} {\mathrm{H}}{{{\mathrm{z}}}^{ - \frac{1}{2}}}$ temperature measurement sensitivity. Combining this innovative, scalable sensor with a newly established simulation model that can transform heating‐laser‐induced temperature change into thermal conductivity, an all‐optical decoupled method is introduced with ≈0.05 W m−1 K−1 precision, which can reduce laser crosstalk. For the first time, the thermal conductivity change of hydrogels during the gelation process is tracked and the existence of variation is demonstrated. The study introduces a rapid, undisturbed technique for measuring microscale thermal conductivity, potentially serving as a valuable tool for cellular thermometry, and highlights the idea that decoupling can reduce crosstalk from different lasers, which is helpful for quantum sensing. [ABSTRACT FROM AUTHOR]

Metasurface enables a new class of "meta‐optics" that can manipulate light at subwavelength scale. Despite that versatile metasurfaces have been demonstrated based on a wide range of materials, the vulnerability of conventional materials to harsh environments, i.e., low resistance to corrosion, low transparency at short wavelength, and lack of thermal/mechanical stability, greatly limit their applications in extreme conditions. Diamond is well‐known for exceptional properties, including the highest thermal conductivity, high damage resistance, extraordinary hardness, and chemical inertness. Therefore, diamond based metasurface is generally expected to benefit from its material merits for extreme use. However, the performance of diamond metasurface in harsh environments remains unexplored up to date. To address this question, this work is designed to study the suitability of single‐crystal diamond based metasurface for broadband applications under harsh environments. As an example, diamond metasurfaces with representative functionalities, including holographic wavefront‐shaping, DUV‐focusing, are investigated under high‐temperature, acid/alkali, and abrasive conditions, respectively. The findings prove the capability of diamond metasurfaces for applications in broadband and harsh conditions, which not only provides a practical and scalable scheme to encode on‐demand functionalities into diamond, but also unlocks a capable candidate to develop robust, large bandwidth, and durable meta‐optics for advanced wavefront shaping under extreme conditions. [ABSTRACT FROM AUTHOR]

Carbonado is a specific variety of diamonds, typical representatives of which are distributed in the diamond placers of Central Africa, Brazil, and Venezuela. Carbonado consists of the microcrystalline aggregates of diamonds, with inclusions of mineral matter. These aggregates appear as fragments that are rounded to varying degrees. Carbonado has been known for a long time, but its primary sources have not been found and its genesis remains unclear. We have substantiated the hypothesis that the most probable precursor of carbonado is shungite. Shungite is a specific form of non-crystalline, non-graphitic, fullerene-like carbon. Shungite rocks, currently known in Karelia (Russia), are natural microdispersed composite materials containing shungite—carbonaceous matter and mineral components of different compositions. The content of carbonaceous matter in shungite rocks is from less than 10% to 98%. The carbon isotopic composition of shungite is light ẟ13C from −25‰ to −40‰. The age of shungite rock is more than 2 billion years old, but earlier shungite was probably much more widespread. Known shungite rocks are more than 2 billion years old, but earlier shungite was probably much more widespread. Shungite rocks could recrystallize into diamond rock upon subduction to high pressure and temperature. The diamond rocks could then be exhumed to the Earth's surface, where they could undergo disruption and reworking with formation of those very fragments that are known as "carbonado". [ABSTRACT FROM AUTHOR]

Olivine is the most abundant mineral in mantle peridotite and a typical inclusion in diamonds, providing essential evidence for the characterization of the diamondiferous lithospheric mantle. Three olivine inclusions in diamonds (OlDia) from Liaoning in the North China Craton (NCC) were exposed for in situ measurements, and the compositional data of 62 other OlDia from Liaoning were collected based on previous reports. The enrichment of TiO2 (>0.1 wt.%) with high Cr# (>50; Cr# = 100Cr/(Cr + Al) by atom) was revealed, despite the predominance of depleted TiO2 contents and high Mg# (92.8–93.2; Mg# =100Mg/(Mg + Fe) by atom) for OlDia. Silica fluid accompanying olivine still trapped in the host diamond was recognized using Raman spectroscopy. Three thermometers were applied to the OlDia, based on the data from Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Electron Probe Micro-Analysis (EPMA), and a temperature range (TLA and TEPMA) of 1080–1380 °C was yielded. With respect to the TLA, Al-in-olivine thermometers were preferred, although there was a smaller deviation between TEPMA and TLA when using the Cr-in-olivine thermometer. The results of these thermometers show a high correlation with TEPMA, enabling their application based on EPMA data. Projections onto 39–42 mW/m2 model geotherms underline a diamondiferous base of the lithospheric mantle beneath the NCC. The lithospheric mantle is characterized by refractory and depleted sections, where enrichment metasomatism may have occurred at the lower roots (161–178 km). [ABSTRACT FROM AUTHOR]

Melting experiments of Fe3C were conducted to 85 GPa in laser‐heated diamond anvil cells with in situ X‐ray diffraction and post‐experiment textural observation. From the determined pressure‐temperature conditions of the melting curve for Fe3C, together with literature data on the melting point of diamond and eutectic point of the system Fe‐Fe3C/Fe7C3 under high pressures, we established a self‐consistent thermodynamic model for high‐pressure melting of the system Fe‐C including the mixing parameters for liquids. The results show that mixing of Fe and C liquids is negatively nonideal from 1 bar to the pressure at the center of the Earth. The departure from ideal mixing becomes progressively larger with increasing pressure, which leads to greatly stabilized liquids under core pressures. The modeled carbon content in eutectic melts under core pressures is 3.3–4.4 wt%. From the Gibbs free energy, we derived an internally consistent parameters for Fe‐C outer cores which included the crystallizing points at their bottoms, isentropic thermal profiles, and densities and longitudinal seismic wave speeds (Vp). While the addition of carbon in excess of the eutectic melt composition effectively reduces the density of iron liquid, the Vp of iron liquid is not greatly changed. Therefore, the low density and high Vp of PREM relative to pure iron cannot be reconciled by an Fe‐C liquid. Therefore, the Earth's core cannot be approximated by the system Fe‐C and should include another light element. Plain Language Summary: The presence or absence of carbon in the Earth's central core has long been discussed in order to account for the observed core density lower than iron because the identification of such light elements in the core will provide critical information about the origin and evolution of the solid Earth. The relevance of carbon in the Earth's core is testable by comparing the density and seismic wave velocities of candidate Fe‐C materials with observations. Here we present a new experiment‐based thermodynamic model for the system Fe‐C. We first determined the melting points of Fe3C to 85 GPa. We then assessed thermodynamic parameters of Fe‐C liquids, from the constrained pressure‐temperature conditions of the melting curve for Fe3C, together with literature data. From the established model, we consistently computed the properties of hypothetical Fe‐C liquid outer cores including the density and longitudinal seismic wave velocity. While a carbon concentration greater than 4 wt% effectively reduces the density of iron liquid, the seismic velocity is not greatly changed, and therefore carbon cannot reconcile the low density and high velocity nature of the Earth's outer core. Therefore, the Earth's core cannot be approximated by the system Fe‐C and should include another light element. Key Points: Melting experiments of Fe3C were conducted to 85 GPa in diamond anvil cells with in situ X‐ray diffraction and textural observationA thermodynamic model for melting of the system Fe‐C which is applicable to the center of the Earth was establishedThe Earth's core cannot be approximated by the system Fe‐C and should include another light element [ABSTRACT FROM AUTHOR]

We studied the effect of femtosecond laser irradiation on the incorporation of n-type forming ions (phosphorus ions, P + and nitrogen ions, N+) into diamond. The (001) surface of a diamond crystal was irradiated by using a femtosecond laser to draw a zigzag pattern in two areas in which the spacing between irradiation lines was controlled to be 2 μm and 1 μm. One half of the crystal surface was P+-implanted and the other half was N+-implanted, both at 600 °C. Electron diffraction patterns obtained from thinned samples showed that the crystallinity of diamond was lost in the densely laser-irradiated area. For both ions, the ion concentration in the laser-irradiated area was higher than that in the nonirradiated area. The highest ion concentration ratio was approximately 5 for the P+-implanted region and greater than 10 for the N+-implanted region. These results support the idea that femtosecond-laser-induced surface modifications can enhance incorporation of n-type forming ions into diamond, with the effect varying according to ion mass. [ABSTRACT FROM AUTHOR]

Diamond has an ultrawide bandgap with excellent physical properties, such as high critical electric field, excellent thermal conductivity, high carrier mobility, etc. Diamond with a hydrogen-terminated (H-terminated) surface has a negative electron affinity (NEA) and can easily produce surface electrons from valence or trapped electrons via optical absorption, thermal heating energy or carrier transport in a PN junction. The NEA of the H-terminated surface enables surface electrons to emit with high efficiency into the vacuum without encountering additional barriers and promotes further development and application of diamond-based emitting devices. This article reviews the electron emission properties of H-terminated diamond surfaces exhibiting NEA characteristics. The electron emission is induced by different physical mechanisms. Recent advancements in electron-emitting devices based on diamond are also summarized. Finally, the current challenges and future development opportunities are discussed to further develop the relevant applications of diamond-based electron-emitting devices. [ABSTRACT FROM AUTHOR]

This study proposes compact, highly sensitive, and stable diamond quantum sensors for a wide range of applications, including biomedical and energy electronics. For enhanced sensitivity and alignment precision within the objective field, a high‐quality, (111)‐oriented 12C‐enriched chemical vapor deposition (CVD) diamond, featuring a nitrogen‐vacancy (NV) axis in the (111) direction, is employed as the sensor. To increase the fluorescence collection efficiency, the laser beam is irradiated from the side surface of the CVD diamond, and fluorescence is detected using a compound parabolic concentrator (CPC) lens. The floor noise level of the magnetic field signal is 44 pT/Hz0.5. An Allan deviation of 1.2 pT over 1000 s of averaging demonstrates stability. This is attributable to the integration of a balancing circuit to cancel out laser noise, alongside mechanisms to compensate for temperature fluctuations and a copper housing to shield against electromagnetic field noise. [ABSTRACT FROM AUTHOR]

This paper presents the reconstruction of the architecture of the lithospheric mantle, including its thermal state and thickness, as well as the scale and efficiency of its sampling by four kimberlites from the Arkhangelsk diamondiferous province: Arkhangelskaya, Lomonosovskaya, V. Grib, and TSNIGRI-Arkhangelskaya. These kimberlites differ in terms of their composition, diamond content, and location. Data presented include the major-element composition of clinopyroxene xenocrysts (>2000 grains), P–T calculations from compositionally filtered Cr-diopside grains, and the reconstruction of local paleogeotherms. Additionally, we used available data on Ni content in peridotitic garnet xenocrysts to calculate their T values and project them onto local Cr-diopside-derived geotherms to reconstruct the vertical distribution of mantle xenocrysts and assess the efficiency of lithospheric mantle sampling by different kimberlites. We identified the presence of a >200 km-thick lithospheric mantle beneath the region at the time of kimberlite emplacement. We also found that the diamond content of the studied pipes was, to some extent, dependent on the following set of factors: (1) the thermal state of the lithospheric mantle; (2) the width of the real "diamond window" marked by mantle xenocrysts, especially by diamond-associated garnets; and (3) the efficiency of lithospheric mantle sampling by kimberlite. The results of this study can be used to inform diamond exploration programs within the region. [ABSTRACT FROM AUTHOR]

This study provides insights into the design and analysis of surface acoustic wave sensors customized for detecting volatile organic compounds (VOCs), utilizing an innovative AlN/diamond/Si multilayered configuration. The results are explored numerically using finite element method simulation within the COMSOL Multiphysics package. The potential of the AlN piezoelectric thin film on diamond on Si substrates for sensor development is examined. The phase velocities, electromechanical coupling coefficient, K 2 , and reflectivity are examined versus the normalized thicknesses of the substrates, considering both Rayleigh and Sezawa wave modes. Additionally, the temperature coefficient of frequency (TCF) is investigated. The results show that the TCF increases with reducing the thickness of the diamond. For instance, at khAIN = 2 where the maximum K 2 can be observed, the TCF increases from −17 to −14 to 3 ppm/°C for khdiamond = 0.5, 0.2, and 0.05, respectively. Furthermore, the sensor sensitivity to gas concentration in the air is examined for several VOCs using a thin polyisobutylene (PIB) layer for sensor demonstration. The study shows a remarkable sensitivity enhancement in sensor sensitivity achieved through the Sezawa wave mode compared to the Rayleigh counterpart. For example, in the case of tetrachloroethene gas (PCE), the sensor sensitivity reaches 197.73 Hz/ppm for the Sezawa mode, as opposed to 62.15 Hz/ppm for the Rayleigh mode. [ABSTRACT FROM AUTHOR]

Crystalline diamond nanoparticles which are 3.6 nm in size adhering to thin-film silicon results in a hydrophilic silicon surface for uniform wetting by electrolytes and serves as a current spreader for the prevention of a local high-lithium-ion current density. The excellent physical integrity of an anode made of diamond on silicon and the long-life and high-capacity-retention cycling performance are thus achieved for lithium-ion batteries. A specific capacity of 1860 mAh/g(si) was retained after 200 cycles of discharge/charge at an areal current density of 0.2 mA/cm2. This is compared to 1626 mAh/g(si) for a thin-film-silicon anode without the additive of diamond nanoparticles. [ABSTRACT FROM AUTHOR]

A comprehensive review of diamonds, in the sense of Scholze, is presented. The diamond formulations of the Fargues-Fontaine curve and B u n G are reviewed. Principal results centered on the diamond formalism in the global Langlands correspondence and the geometrization of the local Langlands correspondence are given. We conclude with a discussion of future geometrizations. [ABSTRACT FROM AUTHOR]

To effectively inhibit the thermal oxidation and thermal failure of diamonds when working in a high–temperature aerobic environment, a Mo–B–C coating was designed and prepared to protect diamonds from oxidation. A two–step synthesis method was used to form coatings with different B contents on diamonds by adjusting the reaction temperature, and the oxidation kinetics and oxidation mechanism of the coated diamonds were investigated in the temperature range of 700°C–1200 °C. The mechanism of diamond protection in this study was the preferential oxidative sacrifice of Mo–B–C coatings to form a stable oxide layer on the diamond surface. For low–B coatings, the four stages of coating oxidation, low-temperature volatilization of MoO3, stable protection by B2O3, and rapid evaporation of B2O3 were experienced sequentially with an increase in temperature. For high–B coatings, the preferential self-healing flow of B2O3 not only inhibited the volatilization of MoO3 but also provided a reducing environment for MoO3 to generate high melting–point MoO2 and Mo2C, which resulted in the formation of a double synergistic protective oxide layer and greatly enhanced the oxidation resistance of diamonds. Meanwhile, the protection of the oxide layer also maintained the compressive strength of diamonds under a high–temperature oxidizing atmosphere, indicating its excellent high temperature applicability. This study provides an effective method for enhancing the high–temperature oxidation resistance and strength of diamonds, which can be effectively applied to the extreme environmental use of diamond tools.

Significance: As the hardest material, diamond is widely used in various cutting and grinding tools. During the preparation process of diamond tools, thermal damage to diamonds is almost inevitable. The thermal damage to diamonds primarily includes graphitization, breakage, cracking, and chemical erosion. Graphitization of diamonds is a lattice transformation process of C atoms essentially, which requires sufficient energy to overcome the energy barrier. Consequently, during the preparation process of diamond tools, diamonds undergo varying degrees of graphitization due to high temperatures and catalyst elements. Breakage and cracking of diamonds primarily orginate from thermal mismatch between the diamond and the matrix metal, including its carbides, where carbides act as inducers of local residual stress, facilitating crack propagation. Chemical erosion of diamonds mainly refers to the process in which C atoms on the surface of diamonds react with active elements through diffusion during the sintering process, therefore deteriorating the diamonds. However, due to the poor wettability of diamonds, it often necessitates the addition of active elements such as Ti, Cr, V, etc., to react with diamonds and improve the holding force. Current suppression technologies for diamond thermal damage can be roughly divided into surface coating of diamonds, adjustment of matrix material properties, and optimization of forming technology. Progress: Diamond surface coating utilizes the unbonded atoms present on the diamond surface, which can react with certain elements at sufficiently high temperatures to form carbides, thereby enhancing the wettability between the matrix metal and the diamonds. Depending on the type of coating, it can generally be classified into metal and non-metal coatings. Metal coatings not only fill and repair defects in diamonds but also improve the bonding strength between the metal and diamonds. Common coating metals include Ni, Ti, W, Cr, and alloys are also selected as coating materials. For non-metal coatings, elements such as B and Si are typically chosen, as they can form carbide layers on the diamond surface, protect the diamond structure, reduce diamond oxidation, and prevent diamonds from being eroded and damaged by strong carbon elements in the matrix material. The choice of matrix material plays a crucial role in mitigating thermal damage to diamonds. Low-melting-point matrix materials can effectively reduce sintering temperature and inhibit the graphitization of diamonds consequently. Furthermore, incorporating appropriate active elements into the matrix material can enhance the interfacial strength between diamond and the matrix, thereby improving the performance of diamond tools. Currently, the modulation of matrix material properties is primarily focused on alloy optimization and composite material development. Alloy optimization aims to reduce diamond thermal damage by refining the alloy composition of the matrix material. Researchers have experimented with elements such as Si, Hf, and Zr, discovering that these elements can mitigate the erosion of diamonds by active elements and reduce diamond thermal damage. Additionally, amorphous Ni-based alloys, due to their low melting point and narrow melting range, have been used as brazing materials to enhance the performance of diamond tools. Composite material development seeks to improve mechanical properties while utilizing suitable reinforcing phases to absorb catalytic elements within the matrix, thereby reducing diamond graphitization. Additionally, reinforcing phases could optimize the diamond interface condition, leading to both increased interfacial strength and reduced diamond thermal damage. Molding technology significantly impacts the lifespan and performance of diamond tools, particularly through parameters such as molding temperature, soaking time, molding pressure, and atmosphere. Molding temperature and soaking time determine grain growth in the matrix, diamond thermal damage, and the interfacial growth between diamond and the matrix. Molding pressure affects the density of the matrix material, which in turn influences its mechanical properties. The atmosphere, typically vacuum or protective, must be carefully controlled, as even trace amounts of moisture or oxygen could lead to diamond oxidation, degrading tool performance and lifespan. Diamond tools are typically manufactured through methods such as hot-press sintering and brazing, while additive manufacturing is emerging as a promising direction in tool fabrication. Conclusions and Prospects: Future research to mitigate diamond thermal damage could focus on three main areas: theoretical analysis of diamond interfaces at the microscale, the establishment of a guidance system matching diamond tool matrix materials with service environments, and investigation of the mechanical behavior of diamonds interfaced during the molding process.

Effective usage of information accumulated over decades of geological exploration requires a tool that allows cataloging, describing, and providing access to both paper and electronic versions of the materials. Despite gradual digitalization of all the major geological exploration processes, there still remains large volume of the materials from previous years on paper media (technical reports, projects, etc.). They continue to be systematically digitized, while new reporting materials are generated in digital form. In addition, thematic scientific articles and publications are annually published. How to combine all the materials and to ensure quick and convenient access to them? There exist various ways to achieve this goal. The Vilyuisk Geological Exploration Expedition (VGRE) of PJSC ALROSA has taken the path of developing a dedicated information system «EFB GRK» designed to store and get access to the information on geological reports, scientific works, articles, etc. Each type of the documents is provided by its own attribute information; several types of the documents are grouped into thematic sections. The system allows one to obtain information on the availability of the projecting and reporting documentation in the archive funds with ability to order and receive and to trace the movement of such documentation.

Abstract This article describes a novel dataset on non‐diamondiferous eclogite and garnet pyroxenite xenoliths from four kimberlite pipes of the Ekati Diamond Mine (Central Slave Craton, Canada). Xenoliths brought to the surface by kimberlite eruptions are direct sources of information on the composition and evolution of the Earth's mantle. Eclogite and garnet pyroxenite xenoliths, specifically, are testimony of subduction into, and metasomatism of, the mantle beneath cratons. Furthermore, these rocks are major hosts for diamond and thus an important part of the deep carbon cycle. The sample suite consists of 41 small xenoliths (2–5 cm) recovered from drill cores. The dataset includes major and trace element concentrations for garnet, clinopyroxene and ilmenite, as well as stable oxygen isotope compositions of garnets. Strontium and neodymium isotopic compositions are reported for garnet and clinopyroxene for four samples which were large enough to allow for analysis. Overall, this dataset significantly expands and complements existing datasets on diamondiferous and non‐diamondiferous xenoliths from the Slave Craton in Canada, furthering our understanding of the composition of the Slave subcratonic lithosphere. The dataset includes several samples with rare mineral assemblages, including an olivine‐bearing eclogite as well as ilmenite and apatite‐bearing garnet‐pyroxenites, and thus provides data shedding light on rarely reported compositional nuances in xenolith suites found in kimberlites.

Diamond is a promising material for multiple applications in quantum information processing and sensing as well as applications in microelectronics. However, diamond devices can be limited by surface defects that compromise charge stability and spin coherence, among others. Improved strategies in plasma etching of diamond could play an important role in minimizing or eliminating these defects. In this work, we explore plasma-assisted atomic scale etching of diamond using argon ions (Ar+), hydrogen ions (H+) and hydrogen atoms (H). We employ classical molecular dynamics (MD) simulations and test several interatomic potentials based on the Reactive Empirical Bond Order (REBO) form with comparisons to a variety of published experimental results. We performed MD simulations of low-energy hydrogen ( ⩽ 50 eV) and argon ( ⩽ 200 eV) ion bombardment of diamond surfaces. Ar+ bombardment can be used to locally smooth initially rough diamond surfaces via the formation of an amorphous C layer, the thickness of which increases with argon ion energy. Subsequent exposure with hydrogen ions (or fast neutrals) will selectively etch this amorphous C layer, leaving the underlying diamond layer mostly intact if the H energy is maintained below about 10 eV. The simulations suggest that combining Ar+ smoothing with selective, near threshold energy H removal of amorphous C can be an effective strategy for diamond surface engineering, leading to more reliable and sensitive diamond color center devices. [ABSTRACT FROM AUTHOR]

Telecommunication of the next generation demands filters that can operate in the 10 GHz range with sufficient bandwidths. For surface-acoustic-wave (SAW) devices this prerequisite translates into high sound velocities and high piezoelectric couplings. Wurtzite AlN on diamond, which exploits the strong piezoelectricity of AlN with the very high SAW velocity of diamond, has been considered a promising platform. A significant boost (up to a factor of 4) of the piezoelectric response can be obtained by alloying AlN with Sc. Here, the main challenge lies in the synthesis of highly-oriented thin (Sc,Al)N films on diamond. In this work, we aim at establishing a platform for SAW devices using plasma-assisted molecular beam epitaxy for the deposition of Sc0.2Al0.8N on diamond. We investigate the structural properties related to SAW generation gearing towards applications at high frequencies. To this end, we prepare (Sc,Al)N thin films on polished polycrystalline diamond wafers and demonstrate the efficient generation of SAW modes with frequencies up to 8 GHz. Systematic studies of the dependence of the SAW velocity and electromechanical coupling coefficient on the Sc0.2Al0.8N film thickness is presented for various SAW modes. Our result demonstrates the potential of this material combination for future application that requires large bandwidth in the ultra-high frequency range. [ABSTRACT FROM AUTHOR]

In 2002, the site of a shipwreck in Cardigan Bay, west Wales, thought to be the final resting place of the fully rigged ship Diamond, was designated by Cadw under the Protection of Wrecks Act 1973. Subsequent investigations into the remains of the vessel on the seabed by the Malvern Archaeological Diving Unit, together with comparisons made against documented historical research relating to Diamond, led to the conclusion that the identity of the ship on this underwater site was almost certainly mistaken. This deduction is, however, not the end of the matter, as while it answered the long-standing question relating to the validity of the name Diamond being ascribed to this shipwreck, it neither threw any light upon the actual identification of the vessel on the site, or the possible location and final resting place of Diamond. This article is an attempt to answer both these two pertinent and outstanding questions. [ABSTRACT FROM AUTHOR]

Objectives: Coating treatment on the surface of diamond particles is an important technique to effectively overcome the problem of difficult bonding between diamond and substrate, and the thermal explosion reaction is a common surface coating technique for diamond particles. However, this technology has disadvantages such as difficulty in separating diamonds from the product and a low proportion of diamonds, which increases its complexity and production costs, greatly limiting the promotion and application of this technology. This article aims to introduce polytetrafluoroethylene (PTFE) into thermal explosion reaction technology to form a coating mainly composed of TiC on the surface of diamond particles. It is expected to optimize the coating preparation process and promote the popularization and application of thermal explosion reaction technology in the field of diamond plating, so as to improve the wear resistance and service life of the diamond tools. Methods: Using two raw material systems, Ti/carbon black/diamond and Ti/carbon black/PTFE/diamond powders, the thermal explosion reaction of Ti/carbon black/diamond is induced by the chemical furnace method, and the intense chemical reaction between PTFE and titanium at low temperature ensures that the Ti/carbon black/PTFE/diamond system directly undergoes a thermal explosion reaction. At the same time, the TiC coating can be generated on the surface of diamond particles by adjusting the ratio of raw materials and triggering the thermal explosion reaction under high temperature conditions. The macroscopic morphology of diamond particles before and after coating is observed and compared by optical microscope to roughly infer the plating condition, and the phase compositions of the coating were analyzed by X-ray diffraction. Then the scanning electron microscope and the energy dispersive spectroscopy are used to observe the surface morphology of diamond particles, determine the elemental compositions, and infer the surface reaction state. Results: The thermal explosion reaction of both raw material systems can form a TiC coating on the surface of diamond. The main phase of the binder reaction product is TiC, and the main phases of the coating on the surface of diamond particles are TiC and Ti. But for the Ti/carbon black/diamond system, the chemical furnace method is needed to induce a thermal explosion reaction. When the diamond mass fraction in the raw material is 30% or lower, the TiC coating on the surface of the diamond particles is good. When a small amount of PTFE is introduced into the Ti/carbon black/diamond system, the reaction between Ti and PTFE releases a large amount of heat, which induces the thermal explosion reaction between Ti and carbon black and synthesizes TiC, and finally forms a TiC coating on the surface of diamond particles. In addition, the system does not need the chemical furnace method to detonate. When the diamond mass fraction in the raw material is less than or equal to 60%, the diamond particle surface coated with TiC coating is good. At the same time, appropriately reducing the content of carbon black in the raw materials can enable diamond to obtain a good TiC coating on its surface even when the mass fraction of diamond is 90% or higher. Conclusions: TiC coatings are prepared on the surface of diamond particles using thermal explosion reaction technology, and the important effects of raw material compositions and PTFE additives on the formation of diamond particles' surface coating are revealed. Adding an appropriate amount of PTFE can directly induce the thermal explosion reaction, which greatly promotes the increase of the proportion of diamond in the raw material, and effectively improves the formation quality of the coating. This can greatly save binder powder, thereby reducing production costs, while obtaining loose powder products that are easy to separate from diamonds. In addition, drawing on the work of this study, other carbide materials (such as SiC) can be analogously extended for coating on the surface of diamond particles, thereby promoting the promotion and the application of thermal explosion reactions in diamond coating.

Diamond is considered a promising detector in radiobiological studies. However, the difference in densities between diamond and tissue imply that their energy deposition spectra are not identical, even for diamond and tissues of the same size. The energy deposition spectrum in diamond was converted to match a tissue sample of the same size. A method based on a mathematical model of energy deposition distribution and the Fourier transform was proposed. The results indicate that the spectra converted from diamond to tissue align closely with those of the tissue. Nevertheless, the applicability of this method is constrained by the mathematical model of energy deposition distribution. Thus, developing a mathematical model that describes the energy deposition spectrum under various conditions can enhance the applicability of this conversion method.

To improve the microstructure and properties of Cu-Sn-Ti brazing alloy through component control, the effect of Si on the microstructure and properties of Cu-20Sn-15Ti brazing filler metals was studied using scanning electron microscopy, X-ray diffraction, and EDS energy spectrum analysis. The results show that the microstructure of Cu-20Sn-15Ti brazing filler metal is composed of large-sized polygonal CuSn3Ti5 phase, eutectic structure and α-Cu phase. A small amount of Si (≤ 2.0wt%) refines the polygonal-shaped CuSn3Ti5 phase in the brazing filler metal and generates small-sized Si3Ti5 phase. In contrast, a larger amount of Si (≥ 3.0wt%) differentiates the polygonal-shape CuSn3Ti5 phase, reduces the proportion of eutectic structure, and increases the content and size of the Si3Ti5 phase. When the Si content increases to 5.0wt%, the filler metal no longer generates polygonal-shaped CuSn3Ti5 phase and eutectic structure. Instead, Ti primarily forms Ti5Si3 phase, and the microstructure mainly consists of Ti5Si3 phase, α- Cu phase, Cu41Sn11 phase, and a small amount of strip-shaped CuSn3Ti5 phase. Compared with Cu and Sn, Si has a stronger chemical affinity with Ti and preferentially reacts with Ti to form Ti5Si3 phase. The three-dimensional structure of Ti5Si3 phase is prismatic and exhibits agglomerated growth characteristics. The coarse strip Ti5Si3 phase has central or lateral pore defects, which are mainly related to the growth mechanism. As the Si content increases, the shear strength of the filler metals shows a trend of “increasing-decreasing-increasing”, and the fracture morphology transitions from a mixed morphology of quasi-cleavage fracture and cleavage fracture to cleavage fracture. The CuSn3Ti5 phase is prone to breakage and cracking, becoming the source of cracking. The presence of coarse CuSn3Ti5 phase in different states can deteriorate the shear strength of the brazing filler metals to some extent.

With the rise of third-generation semiconductors, electronic devices are evolving towards high-power, miniaturization, and integration. Traditional heat dissipation technologies are no longer sufficient to meet the heat dissipation requirements of high heat flux in third-generation semiconductor devices. Temperature accumulation has become a major cause of device failure. Diamond-based materials have excellent thermal properties. Efficient heat dissipation technology based on these materials has become a key direction to solve the high heat flux dissipation problem. This article summarizes the development of diamond-based materials and the main methods for preparing surface microchannels. It reviews the application and development trends of diamond-based materials in the field of efficient heat dissipation. The development and application of diamond-based materials for efficient heat dissipation technology can provide technical support for addressing the problem of high heat flux dissipation.

Owing to extremely large bandgap of 5.5 eV and high thermal conductivity, diamond is recognized as the most important semiconductor. The superconductivity of polycrystalline diamond has always been reported, but there are also many controversies over the existence of superconductivity in bulk single crystal diamond. Besides, it remains a question whether a metallic state exists for such a large bandgap semiconductor. Herein, a single crystal superconducting diamond with a Hall carrier concentration larger than 3 × 1020 cm−3 is realized by co‐doped of boron and nitrogen, with an extremely low resistivity of 2.07 × 10−3 Ω cm at room temperature and dominated acceptor–donor bounded exciton photoluminescence. Furthermore, it is shown that diamond can transform from superconducting to metallic state under similar carrier concentration with tuned carrier mobility degrading from 9.10 cm2 V−1 s−1 or 5.30 cm2 V−1 s−1 to 2.66 cm2 V−1 s−1 or 1.34 cm2 V−1 s−1. Through integrating graphene on a nitrogen and boron heavily co‐doped diamond, a novel transportation behavior in the monolayer graphene similar with superconducting behavior is realized through combining Andreev reflection and exciton‐mediated superconductivity, which may reveal more interesting superconducting behavior of diamond. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chemical functionalization of diamond surfaces by hydrogen is an important method for controlling the charge state of near‐surface fluorescent color centers, an essential process in fabricating devices such as diamond field‐effect transistors and chemical sensors, and a required first step for realizing families of more complex terminations through subsequent chemical processing. In all these cases, termination is typically achieved using hydrogen plasma sources that can etch or damage the diamond, as well as deposited materials or embedded color centers. This work explores alternative methods for lower‐damage hydrogenation of diamond surfaces, specifically the annealing of diamond samples in high‐purity, non‐explosive mixtures of nitrogen and hydrogen gas, and the exposure of samples to microwave hydrogen plasmas in the absence of intentional stage heating. The effectiveness of these methods are characterized by x‐ray photoelectron spectroscopy (XPS), and comparison of the results to density‐functional modelling of the surface hydrogenation energetics implicates surface oxygen ligands as the primary factor limiting the termination quality of annealed samples. Finally, photoluminescence (PL) spectroscopy is used to verify that both the annealing and reduced sample temperature plasma methods are non‐destructive to near‐surface ensembles of nitrogen‐vacancy (NV) centers, in stark contrast to plasma treatments that use heated sample stages. [ABSTRACT FROM AUTHOR]

Diamond as a templating substrate is largely unexplored, and the unique properties of diamond, including its large bandgap, thermal conductance, and lack of cytotoxicity, makes it versatile in emergent technologies in medicine and quantum sensing. Surface termination of an inert diamond substrate and its chemical reactivity are key in generating new bonds for nucleation and growth of an overlayer material. Oxidized high-pressure high temperature (HPHT) nanodiamonds (NDs) are largely terminated by alcohols that act as nucleophiles to initiate covalent bond formation when an electrophilic reactant is available. In this work, we demonstrate a templated synthesis of ultrathin boron on ND surfaces using trigonal boron compounds. Boron trichloride (BCl3), boron tribromide (BBr3), and borane (BH3) were found to react with ND substrates at room temperature in inert conditions. BBr3 and BCl3 were highly reactive with the diamond surface, and sheet-like structures were produced and verified with electron microscopy. Surface-sensitive spectroscopies were used to probe the molecular and atomic structure of the ND constructs' surface, and quantification showed the boron shell was less than 1 nm thick after 1–24 h reactions. Observation of the reaction supports a self-terminating mechanism, similar to atomic layer deposition growth, and is likely due to the quenching of alcohols on the diamond surface. X-ray absorption spectroscopy revealed that boron-termination generated midgap electronic states that were originally predicted by density functional theory (DFT) several years ago. DFT also predicted a negative electron surface, which has yet to be confirmed experimentally here. The boron-diamond nanostructures were found to aggregate in dichloromethane and were dispersed in various solvents and characterized with dynamic light scattering for future cell imaging or cancer therapy applications using boron neutron capture therapy (BNCT). The unique templating mechanism based on nucleophilic alcohols and electrophilic trigonal precursors allows for covalent bond formation and will be of interest to researchers using diamond for quantum sensing, additive manufacturing, BNCT, and potentially as an electron emitter. [ABSTRACT FROM AUTHOR]

Copyright of Diamond & Abrasives Engineering is the property of Zhengzhou Research Institute for Abrasives & Grinding and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The majority of Fabry–Perot interferometer (FPI) tip refractive index (RI) sensors utilize silica optical fiber as the cavity material, with an RI of approximately 1.45. This restricts their applicability in measuring the RI of liquids with an RI of approximately 1.45. Here, we propose a fiber-optic FPI-tip RI sensor by bonding a flat, thin diamond film onto the apex of a single-mode optical fiber. The FPI cavity is constructed from a diamond with an RI of approximately 2.4, theoretically enabling the sensor to achieve an ultrawide RI measurement range of 1 to 2.4. A theoretical comparison of its measurement performance was conducted with that of an FPI-tip RI sensor whose cavity is formed by silica fiber. Additionally, an experimental examination of the device's RI measurement performance was conducted. The results show that the sensor has visibility to the RI unit of −0.4362/RIU in the RI range of 1.33 to 1.40. Combined with other narrow-RI-ranged high-sensitivity sensors, our proposed RI sensor has the potential for use in a wide range of applications. [ABSTRACT FROM AUTHOR]

Tissue engineering, a rapidly advancing field in medicine, has made significant strides with the development of artificial tissue substitutes to meet the growing need for organ transplants. Three-dimensional (3D) porous scaffolds are widely utilized in tissue engineering, especially in orthopedic surgery. This study investigated the fluidic properties of diamond and gyroid structures with varying porosity levels (50–80%) using Computational Fluid Dynamics (CFD) analysis. The pressure and velocity distributions were analyzed, and it was observed that the pressure decreased gradually, whereas the velocity increased in the central area of the surface structures. Specifically, the pressure drop ranged from 2.079 to 0.984 Pa for the diamond structure and from 1.669 to 0.943 Pa for the gyroid structure as the porosity increased from 50% to 80%. It was also found that the permeability increased as the porosity level increased, with values ranging from 2.424 × 10 − 9 to 5.122 × 10 − 9   m 2 for the diamond structure and from 2.966 × 10 − 9 to 5.344 × 10 − 9   m 2 for the gyroid structure. The wall shear stress (WSS) was also analyzed, showing a consistent decrease with increased porosity for both types of structures, with WSS values ranging from 9.903 × 10 − 2 to 9.840 × 10 − 1   P a for the diamond structure and from 1.150 × 10 − 1 to 7.717 × 10 − 2   P a for the gyroid structure. Overall, this study provides insights into the fluidic properties of diamond and gyroid structures, which can be useful in various applications such as tissue engineering. [ABSTRACT FROM AUTHOR]