Carbon Ion Implantation Research Articles

Effect of carbon ion implantation on the superconducting properties of MgB2 bulks prepared by powder-in-sealed-tube method

We studied the effect of carbon (C) ion implantation on the microstructure and superconducting properties of bulk MgB2 prepared by the powder-in-sealed-tube (PIST) method. FESEM and TEM analysis indicate microstructural changes due to carbon ion implantation. DC magnetization measurements reveal a slight improvement of TC and small ΔTC values due to ion implantation. The JC(B) characteristics of implanted samples show a significant enhancement of JC compared with pristine MgB2 at 10 and 20 K. MgB2 samples implanted with 80 keV carbon ions with a dose of 2 × 1016 ions cm−2 show maximum enhancement in JC i.e., 2.07 × 105 A/cm2 at 5 T and 10 K. The flux pinning force density curves are theoretically analyzed using the Dew-Hughes model. The results reveal that significant enhancements in the flux pinning properties are contributed by the normal point defects caused by carbon ion implantation, which acts as a strong pinning center.

Mechanical response of carbon ion implanted ferrite via atomic simulations

Ion implantation plays a nontrivial role in improving the mechanical properties of materials. Unfortunately, the atomic-scale understanding and awareness of the improvement mechanisms remain insufficiently clear and accurate. This paper investigates the nanostructural evolution of carbon ion implanted ferrite and the mechanical response under uniaxial tension leveraging molecular dynamics (MD) simulation, providing direct atomic-scale evidence of alloy strengthening. Regarding nanostructural evolution, grain boundary migration induced by carbon ion implantation becomes significant with increasing doses. However, point defects and amorphous structures caused by collision cascades tend to saturate gradually with increasing implantation doses. Uniaxial tensile test results indicate that the strength of all ion-implanted samples is appreciably enhanced compared to non-implanted samples, especially with an implantation dose of 6.23 × 1013 ions/cm2, where the strength increases by 39%. The underlying strengthening mechanism is that defects, amorphous structures, and lattice distortions induced by ion implantation collectively act as formidable barriers to dislocation motion during plastic deformation, strongly governing dislocation propagation and multiplication. More importantly, the interaction between carbon atoms from ion implantation and dislocations renders the formation of Cottrell atmospheres, which further enhances solid solution strengthening by pinning dislocations. These results advancing the fundamental understanding of nanostructural evolution and strengthening mechanism under ion implantation suggest a mechanistic strategy for augmenting alloy strength.

The role of ion beam in modification of CuO@NiO@ZnO/GO electrode for supercapacitor application

Recently, mixed transition metals oxides became emerging electrode materials for energy storage devices such as supercapacitors, batteries, etc. due to their high electrochemical performances. In this study, mixed transition metals including Copper oxide (CuO), Nickel oxide (NiO) and Zinc oxide (ZnO) in conjunction with graphene oxide (GO) were used to fabricate electrode materials for the supercapacitor applications adopting hydrothermal process. The features of the as-fabricated electrodes were further modified by irradiating them with 5.0 MeV C++ ions with varying fluence rates. Monte Carlo-based Stopping and Range of Ions in Matter (SRIM) simulation code was utilized to analyze the ion implantation-induced processes inside the target electrode. Electrodes' crystal features, morphologies, elemental compositions, and vibrational and optical characteristics were examined employing X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM) coupled with energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and UV–visible spectroscopy, respectively. Electrochemical impedance spectroscopy (EIS), galvanostatic charge-discharge (GCD), and cyclic voltammetry (CV) were among various techniques engaged to analyze the electrochemical properties of the pristine and post-implanted electrode materials. The electrochemical findings from CV and GCD for the electrode implanted with 5.0 × 1015 ionscm−2, which offered the best result presented enhanced specific capacitances of 1250 and 1350 Fg−1 at a scan rate 1.0 mVs−1 and current density 0.5 Ag−1 respectively. This study revealed that carbon ion implantation at a fluence 5.0 × 1015 ionscm−2 could prompt the enhancement of the electrochemical properties of this fabricated electrode material.

Detection of carbon dioxide and hydrogen peroxide on the stratified surface of Charon with JWST

Charon, Pluto’s largest moon, has been extensively studied, with research focusing on its primitive composition and changes due to radiation and photolysis. However, spectral data have so far been limited to wavelengths below 2.5 μm, leaving key aspects unresolved. Here we present the detection of carbon dioxide (CO2) and hydrogen peroxide (H2O2) on the surface of Charon’s northern hemisphere, using JWST data. These detections add to the known chemical inventory that includes crystalline water ice, ammonia-bearing species, and tholin-like darkening constituents previously revealed by ground- and space-based observations. The H2O2 presence indicates active radiolytic/photolytic processing of the water ice-rich surface by solar ultraviolet and interplanetary medium Lyman-α photons, solar wind, and galactic cosmic rays. Through spectral modeling of the surface, we show that the CO2 is present in pure crystalline form and, possibly, in intimately mixed states on the surface. Endogenically sourced subsurface CO2 exposed on the surface is likely the primary source of this component, with possible contributions from irradiation of hydrocarbons mixed with water ice, interfacial radiolysis between carbon deposits and water ice, and the implantation of energetic carbon ions from the solar wind and solar energetic particles.

Molecular dynamics simulation study of nitrogen vacancy color centers prepared by carbon ion implantation into diamond

Nitrogen vacancy (NV) color centers in diamond have useful applications in quantum sensing and fluorescent marking. They can be generated experimentally by ion implantation, femtosecond lasers, and chemical vapor deposition. However, there is a lack of studies of the yield of NV color centers at the atomic scale. In the molecular dynamics simulations described in this paper, NV color centers are prepared by ion implantation in diamond with pre-doped nitrogen and subsequent annealing. The differences between the yields of NV color centers produced by implantation of carbon (C) and nitrogen (N) ions, respectively, are investigated. It is found that C-ion implantation gives a greater yield of NV color centers and superior location accuracy. The effects of different pre-doping concentrations (400–1500 ppm) and implantation energies (1.0–3.0 keV) on the NV color center yield are analyzed, and it is shown that a pre-doping concentration of 1000 ppm with 2 keV C-ion implantation can produce a 13% yield of NV color centers after 1600 K annealing for 7.4 ns. Finally, a brief comparison of the NV color center identification methods is presented, and it is found that the error rate of an analysis utilizing the identify diamond structure + coordination analysis method is reduced by about 7% compared with conventional identification methods.

Structural, electronic, and optical properties of 6H-SiC layers synthesized by implantation of carbon ions into silicon

Systematic studies of the gradual fabrication by means of carbon ion-implantation of high-quality 6H-SiC layers on silicon surfaces have been carried out. The fluence of carbon ions varied from 5 × 1015 cm−2 to 1017 cm−2. Results of first-principle calculations, X-ray diffraction (XRD), and Raman spectroscopy demonstrate the amorphization of silicon substrate without any tendency to the segregation of carbon in the samples synthesized at low fluencies. The formation of a SiO2-like structure at this stage was also detected. X-ray photoelectron spectroscopy (XPS), XRD, and Raman spectroscopy demonstrate that an increase in carbon content at 1017 cm−2 fluence leads to the growth of 6H-SiC films on the surface of the amorphous silicon substrate. Atomic force microscopy (AFM) data obtained also demonstrates the decreasing of surface roughens after the formation of SiC film. XPS and Raman spectra suggest that excessive carbon content leaves the SiC matrix via the formation of an insignificant amount of partially oxidized carbon nanostructures. Optical measurements also support the claim of high-quality 6H-SiC film formation in the samples synthesized at 1017 cm−2 fluence and demonstrate the absence of any detectable contribution of nanostructures formed from excessive carbon on the optical properties of the material under study.

Direct Synthesis of Layer‐Tunable and Transfer‐Free Graphene on Device‐Compatible Substrates Using Ion Implantation Toward Versatile Applications

Direct synthesis of layer‐tunable and transfer‐free graphene on technologically important substrates is highly valued for various electronics and device applications. State of the art in the field is currently a two‐step process: a high‐quality graphene layer synthesis on metal substrate through chemical vapor deposition (CVD) followed by delicate layer transfer onto device‐relevant substrates. Here, we report a novel synthesis approach combining ion implantation for a precise graphene layer control and dual‐metal smart Janus substrate for a diffusion‐limiting graphene formation to directly synthesize large area, high quality, and layer‐tunable graphene films on arbitrary substrates without the post‐synthesis layer transfer process. Carbon (C) ion implantation was performed on Cu–Ni film deposited on a variety of device‐relevant substrates. A well‐controlled number of layers of graphene, primarily monolayer and bilayer, is precisely controlled by the equivalent fluence of the implanted C‐atoms (1 monolayer ~4 × 1015 C‐atoms/cm2). Upon thermal annealing to promote Cu‐Ni alloying, the pre‐implanted C‐atoms in the Ni layer are pushed toward the Ni/substrate interface by the top Cu layer due to the poor C‐solubility in Cu. As a result, the expelled C‐atoms precipitate into a graphene structure at the interface facilitated by the Cu‐like alloy catalysis. After removing the alloyed Cu‐like surface layer, the layer‐tunable graphene on the desired substrate is directly realized. The layer‐selectivity, high quality, and uniformity of the graphene films are not only confirmed with detailed characterizations using a suite of surface analysis techniques but more importantly are successfully demonstrated by the excellent properties and performance of several devices directly fabricated from these graphene films. Molecular dynamics (MD) simulations using the reactive force field (ReaxFF) were performed to elucidate the graphene formation mechanisms in this novel synthesis approach. With the wide use of ion implantation technology in the microelectronics industry, this novel graphene synthesis approach with precise layer‐tunability and transfer‐free processing has the promise to advance efficient graphene‐device manufacturing and expedite their versatile applications in many fields.

Enhanced specific capacitance, structural, optical, and morphological study of carbon ions incorporated into the lattice of ZrCuO2 nanoparticle synthesized by hydrothermal method

In this study, ZrCuO2 nanoparticles were made using the hydrothermal method and potassium hydroxide as the precipitant. The material was irradiated with 500 keV carbon (C++) ions at doses of 1 × 1014, 1 × 1016, and 1 × 1018 ions/cm2. The ZrCuO2 nanoparticles exhibited cubic crystal structures with clear peaks on different orientation planes, both before and after being irradiated with carbon ions (C++). By incorporating carbon ions, the peak intensity and crystallinity of CuO nanostructures were enhanced. The non-irradiated micrographs display groups of tiny pebbles, whereas the carbon ion irradiated ZrCuO2 nanoparticles show flake-like structures. The material became denser because of carbon ion irradiation, which increased the carrier concentration. The absorption rate increase of the material reveals the impact of a carbon ion on irradiated ZrCuO2 nanoparticles. The absorbance of ZrCuO2 nanoparticles is enhanced through carbon ion implantation. The material has a bandgap energy of 1.95 eV without irradiation. The bandgap energy range of the irradiated material is 1.55–1.82 eV. The energy bandgap of the synthesized material was reduced because of carbon ion irradiation. The ZrCuO2 nanoparticle electrode with a specific capacitance value of 225 F/g. The electrodes prepared at 500 keV carbon (C++) ions with dosages of 1 × 1014, 1 × 1016, and 1 × 1018 ions/cm2 yielded specific capacitance values of 275 F/g, 300 F/g, and 312.5 F/g, respectively.

Formation of yttrium oxalate phase filled by carbon clusters on the surface of yttrium oxide films

In the current paper, we report the results of surface modification of cubic Y2O3 films employing carbon-ion implantation. The characterization results demonstrate the formation of a stable yttrium oxalate-based structure with cavities filled with carbon clusters. Theoretical simulations demonstrate that the incorporation of eighteen-atom carbon clusters into the cavities of Y2(C2O4)3 does not lead to valuable changes in the crystal structure of yttrium oxalate. X-ray diffraction and optical measurements demonstrate that the subsurface bulk area of cubic yttrium oxide remains unperturbed. The oxalate “skin” thickness with embedded carbon clusters is estimated to be approximately 10 nm. The prospective employing the method to manage optical properties and increase the biocompatibility of yttria and lanthanide oxides are discussed.

The effects of carbon ion implantation on wettability, abrasion, thermal and anti-corrosion stabilities of laser ablated super-hydrophobic Nitinol surface

Comparing with pure laser irradiation, the hybrid fabrication using laser ablation and chemical modification is one of the widely used techniques to obtain bio-inspired super-hydrophobic surface. Nevertheless, conventional surface chemical modification techniques have faced challenges including the detachment of micro-nano structures and the instability of super-hydrophobic surfaces. This research introduces an innovative method for creating extremely stable super-hydrophobic surfaces on NiTi alloy through a combination of laser exposure, carbon ion implantation, and modification with fluoroalkylsilane (FAS). Surface morphology and chemical component were systematically investigated to reveal the formation mechanism of super-hydrophobicity. Besides, its abrasion stability, thermal stability and corrosion resistance stability of this kind of super-hydrophobic surface were also investigated. And the corresponding stability improvement mechanisms were further revealed.

Optical ridge waveguides in Nd3+‐doped fluorophosphate glasses fabricated by carbon ion implantation and femtosecond laser ablation

AbstractIn this work, the ridge waveguide was formed by the femtosecond laser ablation with a central wavelength of 0.808 μm and a speed of 50 μm/s on the planar Nd3+‐doped fluorophosphate glass waveguide that was fabricated by the C3+ ion implantation with an energy of 6.0 MeV and a fluence of 1.0×1012 C3+s/mm2. The mechanism of the ion‐implanted waveguide was discussed by the Stopping and Range of Ions in Matter 2013. The cross‐section morphology of the ridge waveguide was captured by an optical microscope. Its mode characteristics were analyzed by the end‐face coupling method. The ridge Nd3+‐doped fluorophosphate glass waveguides have potential as fundamental structures for many optoelectronic devices including waveguide amplifiers and lasers.

Room Temperature Ion Beam Synthesis of Ultra-Fine Molybdenum Carbide Nanoparticles: Toward a Scalable Fabrication Route for Earth-Abundant Electrodes.

Molybdenum carbides are promising low-cost electrocatalysts for electrolyzers, fuel cells, and batteries. However, synthesis of ultrafine, phase-pure carbide nanoparticles (diameter<5nm) with large surface areas remains challenging due to uncontrollable agglomeration that occurs during traditional high temperature syntheses. This work presents a scalable, physical approach to synthesize molybdenum carbide nanoparticles at room temperature by ion implantation. By tuning the implantation conditions, various molybdenum carbide phases, stoichiometries, and nanoparticle sizes can be accessed. For instance, molybdenum ion implantation into glassy carbon at 30keV energy and to a fluence of 9×1016 atcm-2 yields a surface η-Mo3C2 with a particle diameter of (10±1)nm. Molybdenum implantation into glassy carbon at 60keV to a fluence of 6×1016 atcm-2 yields a buried layer of ultrafine γ'-MoC/η-MoC nanoparticles. Carbon ion implantation at 20keV into a molybdenum thin film produces a 40nm thick layer primarily composed of β-Mo2C. The formation of nanoparticles in each molybdenum carbide phase is explained based on the Mo-C phase diagram and Monte-Carlo simulations of ion-solid interactions invoking the thermal spike model. The approaches presented are widely applicable for synthesis of other transition metal carbide nanoparticles as well.

C+ ion implanted single crystal diamond with amorphous surface for efficient oxygen evolution catalysis

Oxygen evolution reaction (OER) is critical in water splitting for green hydrogen gas production due to its sluggish kinetics; however, commercial OER catalysts commonly suffer from high cost, low catalytic activity and poor stability. Herein, we developed a C+ ion implantation method to modify single crystal diamond, and the resultant surface amorphous layer not only raised the active site number but also increased the content of the C=O group, thus significantly improving the OER activity. The C+ ion implanted high-temperature and high-pressure (C+-HTHP) and chemical vapor deposition (C+-CVD) diamonds both exhibit low OER overpotential with η10 of 317 mV and 325 mV respectively, superior to those of HTHP diamond (360 mV), CVD diamond (395 mV) and RuO2 (364 mV). The potentiostatic testing shows that the C+ implanted diamonds almost didn't undergo the rise of OER overpotential upon catalysis for more than 12 h at a current density of 10 mA cm−2, suggesting a high catalytic stability, owing to the strong bonding between single crystal diamond and amorphous carbon layer. For the first time, we utilized carbon ion implantation to prepare diamond-based high-performance OER catalyst, which broadens the understanding of carbon-based materials in OER catalysis.

Microstructure evolution and electrochemical properties of carburized CSS-42L steel by high dose carbon ion implantation

The precipitation of Cr-rich carbides creates significant chromium depletion zones against the steel matrix, which are more sensitive to pitting corrosion. In this work, high dose carbon ion implantation was introduced to eliminate the negative effect of Cr-rich carbides precipitated in carburized CSS-42L steel. X-ray photoelectron spectroscopy (XPS) analysis reveals the co-existence of graphite bonds and carbide bonds for the carbon implanted samples. Amorphization transformation for Cr-rich carbides and precipitation of nanocrystalline Fe2C carbides in the implanted layer are confirmed by transmission electron microscopy (TEM) and glancing incidence x-ray diffraction (GIXRD) investigations. The electrochemical results indicated that the microstructure evolution induced by carbon ion implantation was beneficial in improving the corrosion property of carburized CSS-42L steel, in which the intergranular corrosion was suppressed and the corrosion degree was also modified.

Controlling the beam angle spread of carbon implantation for improvement of bin map defect in V-NAND flash memory

As the shrinkage of devices accelerates and the vertical layers increase, beam angle spread of carbon ion implantation (C IIP) for the silicon selective epitaxial growth (Si-SEG) areas in V-NAND is one of the most critical parameters related with bin map defects. The roles of C IIP in Si-SEGs are that it can suppress channeling effect of boron IIP and diffusion limitation of boron dopants during subsequent annealing processes. In this study, beam angle spread was reduced by 36% and the center-to-edge beam angle skew of wafer was reduced to less than 1° by optimizing the specification of tracking magnet and the beam angle mean. After applying the improved process conditions and effective interlocks, the bin defective rate was controlled less than 0.5% successfully.

Spectrally stable nitrogen-vacancy centers in diamond formed by carbon implantation into thin microstructures

The nitrogen-vacancy center (NV) in diamond, with its exceptional spin coherence and convenience in optical spin initialization and readout, is increasingly used both as a quantum sensor and as a building block for quantum networks. Employing photonic structures for maximizing the photon collection efficiency in these applications typically leads to broadened optical linewidths for the emitters, which are commonly created via nitrogen ion implantation. With studies showing that only native nitrogen atoms contribute to optically coherent NVs, a natural conclusion is to either avoid implantation completely or substitute nitrogen implantation by an alternative approach to vacancy creation. Here, we demonstrate that implantation of carbon ions yields a comparable density of NVs as implantation of nitrogen ions and that it results in NV populations with narrow optical linewidths and low charge-noise levels even in thin diamond microstructures. We measure a median NV linewidth of 150 MHz for structures thinner than 5 μm, with no trend of increasing linewidths down to the thinnest measured structure of 1.9 μm. We propose a modified NV creation procedure in which the implantation is carried out after instead of before the diamond fabrication processes and confirm our results in multiple samples implanted with different ion energies and fluences.

Effect of Carbon Ion Implantation and Xenon Ion Irradiation on the Tribological Properties of Titanium and Ti6Al4V Alloy

Effect of Carbon Ion Implantation and Xenon Ion Irradiation on the Tribological Properties of Titanium and Ti6Al4V Alloy

A Combination of Ion Implantation and High‐Temperature Annealing: The Origin of the 265 nm Absorption in AlN

The commonly observed absorption around 265 nm in AlN is hampering the outcoupling efficiency of light‐emitting diodes (LEDs) emitting in the UV‐C regime. Carbon impurities in the nitrogen sublattice (CN) of AlN are believed to be the origin of this absorption. A specially tailored experiment using a combination of ion implantation of boron, carbon, and neon with subsequent high‐temperature annealing allows to separate the influence of intrinsic point defects and carbon impurities regarding this absorption. Herein, the presented results reveal the relevance of the intrinsic nitrogen‐vacancy defect VN. This is in contradiction to the established explanation based on CN defects as the defect causing the 265 nm absorption and will be crucial for further UV‐LED improvement. Finally, in this article, a new interpretation of the 265 nm absorption is introduced, which is corroborated by density functional theory (DFT) results from the past decade, which are reviewed and discussed based on the new findings.

Adhesion Strength of Amorphous Carbon Films Deposited on a Trench Sidewall

Hydrogenated amorphous carbon (a-C:H) films were deposited on the sidewall of 3-mm-wide stainless steel or Si trench, and the adhesion strength of the films was evaluated using a micro-scratch tester. Particularly, the effects of carbon ion implantation and Si-containing interlayer (a-SiCx:H) as the pretreatments on the adhesion strength of the a-C:H films prepared on the trench sidewall were investigated. It was found that both carbon ion implantation and interlayer improved the adhesion strength of the a-C:H films deposited on the trench sidewalls. In addition, the carbon ion implantation dominated the adhesion strength of the a-C:H films for the Si substrates, and the interlayer for the stainless steel substrates. In the case of the stainless steel substrates, the carbon was accumulated on the surface of the trench sidewall instead of implantation, whereas the carbon ions were implanted to the Si substrates on the trench sidewall to form a mixing layer. The a-SiCx:H interlayer forms Fe–Si bonds between the stainless steel substrate and the interlayer, which is thought to improve the adhesion strength. It was also found that there is a negative correlation between the trench depth and the adhesion strength regardless of the pretreatment methods.

Asiaticoside Combined With Carbon Ion Implantation to Improve the Biocompatibility of Silicone Rubber and to Reduce the Risk of Capsule Contracture.

Capsular contracture caused by silicone rubber is a critical issue in plastic surgery that urgently needs to be solved. Studies have shown that carbon ion implant in silicone rubber (carbon silicone rubber, C-SR) can significantly improve the capsular structure, but the effect of this improvement only appear 2months or later. In this study, asiaticoside combined with carbon silicone rubber was used to explore the changes in the capsule to provide a reference for the treatment of capsule contracture. Human fibroblasts (HFF-1) were used for in vitro experiments. The combined effect of asiaticoside and carbon silicone rubber on cell proliferation was determined by the CCK8 method, cell migration changes were measured by Transwell assays, cell cycle changes were measured by flow cytometry, and the expression levels of fibroblast transformation markers (vimentin and α-SMA), collagen (Col-1A1) and TGF-β/Smad signaling pathway-related proteins (TGF-β1, TβRI, TβRII and Smad2/3) were detected by immunofluorescence. In vivo experiments were carried out by subcutaneous implantation of the material in SD rats, and asiaticoside was oral administered simultaneously. WB and ELISA were used to detect changes in the expression of TGF-β/Smad signaling pathway-related proteins. TGF-β/Smad signaling pathway proteins were then detected and confirmed by HE, Masson and immunohistochemical staining. The results shown that asiaticoside combined with carbon ion implantation inhibited the viability, proliferation and migration of fibroblasts on silicone rubber. In vitro immunofluorescence showed that the secretion levels of α-SMA and Col-1A1 were significantly decreased, the transformation of fibroblasts into myofibroblasts was weakened, and the TGF-β/Smad signaling pathway was inhibited. In vivo experimental results showed that asiaticoside combined with carbon silicone rubber inhibited TGF-β1 secretion and inhibited the TGF-β/Smad signaling pathway, reducing the thickness of the capsule and collagen deposition. These results imply that carbon silicone rubber combined with asiaticoside can regulate the viability, proliferation and migration of fibroblasts by inhibiting the TGF-β/Smad signaling pathway and reduce capsule thickness and collagen deposition, which greatly reduces the incidence of capsule contracture.