Nitrogen Implantation Research Articles

Triple nitrogen-vacancy centre fabrication by C5N4Hn ion implantation

Quantum information processing requires quantum registers based on coherently interacting quantum bits. The dipolar couplings between nitrogen vacancy (NV) centres with nanometre separation makes them a potential platform for room-temperature quantum registers. The fabrication of quantum registers that consist of NV centre arrays has not advanced beyond NV pairs for several years. Further scaling up of coupled NV centres by using nitrogen implantation through nanoholes has been hampered because the shortening of the separation distance is limited by the nanohole size and ion straggling. Here, we demonstrate the implantation of C5N4Hn from an adenine ion source to achieve further scaling. Because the C5N4Hn ion may be regarded as an ideal point source, the separation distance is solely determined by straggling. We successfully demonstrate the fabrication of strongly coupled triple NV centres. Our method may be extended to fabricate small quantum registers that can perform quantum information processing at room temperature.

Corrosion resistance and cytotoxicity of AZ31 magnesium alloy with N+ ion implantation

ABSTRACTIn recent years, magnesium (Mg) alloys, as biodegradable materials, have attracted increasing interest in cardiovascular and orthopedic applications. However, their high corrosion rates hinder the development of Mg alloys in clinical treatment. To improve this condition, the research described here focuses on addressing techniques that are critical to reducing the corrosion rate of Mg alloys. We applied nitrogen (N+) ion implantation into AZ31 Mg alloy to modify their surface properties, and examined the cytotoxicity of the samples through cell culture experiment. The proposed research investigates the following aspects that are important for the design of biomaterials based on Mg alloy: (a) the potential role of N+ ion implantation in reducing corrosion of Mg alloy; (b) non-toxicity for Mg alloy implanted with N+ ion. Our results indicate that AZ31 Mg alloy with N+ ions implantation is a very promising biological material, which has a profound impact on the development of biomedicine.

The effect of N+ ion-implantation on the corrosion resistance of HiPIMS-TiN coatings sealed by ALD-layers

Plasma immersion ion implantation (PIII) was studied as a pretreatment method for improving the surface activity of TiN coatings deposited by high power impulse magnetron sputtering (HiPIMS) before being sealed with an ALD (Atomic layer deposition)-Al2O3 hybrid coating. The effect of different implantation energy and dose of nitrogen plasma on the microstructure and surface morphology of TiN coatings were investigated, and the surface morphology and fracture cross-section images of TiN/Al2O3 hybrid coatings with and without PIII pretreatment were compared. The corrosion protection properties were explored with linear sweep voltammetry in 3.5% NaCl solution at the room temperature. The results indicated that the N+ pre-ion-implantation had a significant influence on the microstructure and surface morphology of TiN coatings. With the increase of ion implantation energy and dose, TiN coatings gradually alter from the preferred orientation (200) to a mixture of (200) and (111), accompanied by the decrease of grain size on the surface. Moreover, the PIII pretreatment of the TiN coatings could significantly shorten the incubation time of the nucleation of ALD films, leading to a denser but thinner (at the same deposition cycles) layer of Al2O3, which plays a positive role in corrosion resistance. The coverage of ALD-Al2O3 films was improved with the increase of the nitrogen ion implantation energy and dose, resulting in better corrosion protection.

Glass Hardness Modification by Means of Ion Implantation: Electronic Doping versus Surface Composition Effect

AbstractCritical load measurements point to an improvement in the hardness of a soda–lime glass upon nitrogen implantation. In order to determine whether this improvement originates from electronic doping or surface composition changes induced by ion implantation, a theoretical approach using quantum‐chemical and force‐field methods combined with X‐ray photoelectron spectroscopy is performed. The results indicate that neither an electronic effect nor a lattice distortion appear to be the primary cause of the hardness improvement. It is rather a change in the surface composition leading to a more densely cross‐linked and stiffer silica network at the top surface of the glass which is at the origin of this improvement.

The Effect of Damage of a Plasma-Treated Polyurethane Surface on Bacterial Adhesion

Abstract—Elastic polyurethanes are flexible materials used in biomedical products. Plasma treatment is a promising method of surface modification. However, external deformation of the elastic substrate could damage the modified layer and provoke various undesirable consequences. In this work, two elastic polyurethanes with different stiffness have been studied. The materials were treated by plasma immersion implantation of nitrogen ions (with the energy of 1 and 3 keV). As a result, the relief and hydrophobicity of the surfaces changed such that the adhesion of both Gram-positive (Staphylococcus) and Gram-negative (Escherichia coli) bacteria decreased. Cyclic uniaxial deformation damages the treated surfaces: transverse cracks and longitudinal folds are formed. These changes increase bacterial adhesion to values that exceeding that on untreated materials. All features of the modified surfaces correlated both with the properties of original substrate and with the treatment parameters. Bacterial adhesion is affected mainly by the peculiarities of the relief structure.

Optical coherence of diamond nitrogen-vacancy centers formed by ion implantation and annealing

The advancement of quantum optical science and technology with solid-state emitters such as nitrogen-vacancy (NV) centers in diamond critically relies on the coherence of the emitters' optical transitions. A widely employed strategy to create NV centers at precisely controlled locations is nitrogen ion implantation followed by a high-temperature annealing process. We report on experimental data directly correlating the NV center optical coherence to the origin of the nitrogen atom. These studies reveal low-strain, narrow-optical-linewidth ($<500$ MHz) NV centers formed from naturally-occurring $^{14}$N atoms. In contrast, NV centers formed from implanted $^{15}$N atoms exhibit significantly broadened optical transitions ($>1$ GHz) and higher strain. The data show that the poor optical coherence of the NV centers formed from implanted nitrogen is not due to an intrinsic effect related to the diamond or isotope. These results have immediate implications for the positioning accuracy of current NV center creation protocols and point to the need to further investigate the influence of lattice damage on the coherence of NV centers from implanted ions.

Technical Note: Life-time improvement and the cutting forces in nitrogen-implanted drills during wood-based material machining

This study explored the effects of nitrogen (N) ion implantation of drills for wood-based materials. Modification of a tool’s surface is a common process of prolonging its lifetime. For the purpose of this study, ion implantation was used for modification of drills commonly used in the furniture industry. The rake face of high-speed steel drills was implanted with different doses of nitrogen ions. Durability tests were conducted with the use of a computerized numerical control woodworking machine used for drilling laminated particleboards. The cutting force and drilling torque were measured. The obtained results were presented as wear curves of the examined drill bits. Based on the results, tools implanted with nitrogen ions at different doses had a longer tool life.

Effect of Nitrogen Implantation on the Structure and Properties of Austenitic Corrosion-Resistant Steels

Work is devoted to studying the effect of implantation of nitrogen ions into the surfaceof austenitic stainless steels to improve their functional properties. Four grades ofaustenitic corrosion-resistant steels 02H16N10M2, 08H15AG10D2, 06H15AG9NM2 and09H15AG9ND2 were taken after cold plastic deformation and annealing from 680 ∘Cin water and subsequent implantation with N+ ions with different radiation dose: 0,01 и0,1%. It was found that irradiation of austenitic stainless steels with nitrogen ions can beconsidered an effective way to increase the hardness and yield strength of steels in theoperation in a corrosive environment.

Defect Formation under Nitrogen-Ion Implantation and Subsequent Annealing in GaAs Structures with an Uncovered Surface and a Surface Covered with an AlN Film

The concentration profiles of defects produced in structures upon the implantation of nitrogen ions into GaAs epitaxial layers with an uncovered surface and that covered with an AlN film and subsequent annealing are studied. The ion energies and the implantation doses are chosen so that the nitrogen-atom concentration profiles coincided in structures of both types. Rutherford proton backscattering spectra are measured in the random and channeling modes, and the concentration profiles of point defects formed are calculated for the samples under study. It is found that the implantation of nitrogen ions introduces nearly the same number of point defects into structures of both types, and the formation of an AlN film by ion-plasma sputtering is accompanied by the formation of an additional number of defects. However, the annealing of structures of both types leads to nearly the same concentrations of residual defects.

Tantalum/ Nitrogen and n-type WO3 semiconductor/FTO structures as a cathode for the future of nano devices

In the last decades an important number of research papers published on nano chip electrode and cathode electrochromic materials. Tantalum (Ta) with so high melting point can be as a good candidate for the future of nano chip devices. However, its surface has not enough trap centers and/or occupation states, so nitrogen ions exposed on Ta surafce, may solve this problem. For this purpose, in the present work, samples of tantalum with purities of 99.99% (0.58 mm thickness) were implanted by nitrogen ions. The ions’ implantation process was performed at 30 keV and also at different doses which were in the range between 1017- 1018 ions/cm2. The electrical, nano structural characteristics, sample surface topography characteristic were investigated on Tantalum nitrides (Ta/N) structures by looking at current–voltage (I–V) curves.In addition to Ta/N, WO3powders as a famous EC metal oxide, a silver metal deposited on fluorine doped tin oxide (FTO)-coated glass andmultilayer structure with using the physical vapor deposition (PVD) apparatus are formed. Some techniques such as uv- visible, Atomic Force Microscopy (AFM) and X Ray Diffraction (XRD) have been used. The obtained results show the formation of hexagonal tantalum nitride (TaN0.43), and more trap centers of sample surface (in comparison to current cathode material of EC device). The electrical resistivity of the tantalum after nitrogen implantation is also found to increase with ion doses.Therefore, Ta/N with more trap centers (rough surface) can be suggested as a good element of the future of EC and nano devices.

The regularities of surface corrugation of polyacrylonitrile based carbon fibers under high-fluence ion irradiation

The regularities of surface corrugation of polyacrylonitrile based carbon fibers reinforcing composite KUP-VM has been studied experimentally after high-fluence 30 keV Ne+, 20 and 30 keV Ar+, 30 keV N2+ ion irradiation at target temperatures ranging from 100 to 600 °C. It was found that periodic corrugated structure parameters, such as the angles of the inclination β of the corrugations and their fraction on the fiber surface have strong temperature dependences. The periodicity of corrugations for all used ions slightly decreases with increasing temperature and is of the order of hundreds of nanometers. For neon and argon ions the corrugation inclination angles and the fraction in contrary of nitrogen ions show minima at the temperatures near 400 °C which corresponds to the minimum of radiation-induced dimensional changes in carbon materials. The depth of the minima at 400 °C depends on the competition of the processes of ion-induced plastic deformation of carbon materials and ion bombardment sputtering. For nitrogen ions the inclination angles increase with temperature so that at temperature ∼270 °C they reach maximum values ∼40°, staying at this level at subsequent temperature elevation up to 600 °C. The qualitative difference in the temperature dependences of fiber corrugation for noble gas ions and nitrogen ones is connected to nitrogen chemical activity and the creation of CN bonds under nitrogen ion implantation.

Effect of nitrogen ion implantation on phases, crystallization behaviors and magnetic properties of amorphous Fe-Si-B ribbons

Abstract Nitrogen ion implantation is employed to improve the soft magnetic properties of commercial amorphous Fe-Si-B ribbons. The effects of implantation dose and acceleration voltage on the micro-structure, crystallization behavior and magnetic properties are systematically investigated. 1 × 1016 ions cm−2 is determined to be the most suitable dose value to generate one layer with nitrogen implanted as well as keeping the ribbon amorphous. The maximum saturation magnetization of 1.69 T is obtained under this dose, which may be due to the contribution of the formed nanostructured nitride with higher magnetization. Continuing to increase the dose, the magnetization starts to decrease because of the crystallization of the amorphous matrix. Under different acceleration voltages, the structure of the Fe-Si-B ribbons keeps amorphous. Moreover, the largest magnetization is achieved at 150 kV.

Comparative study of nitrogen implantation effect on mechanical and tribological properties of Ti-6Al-4V and Ti-10Zr-10Nb-5Ta alloys

The effect of nitrogen implantation on mechanical and tribological properties of Ti-6Al-4V and Ti-10Zr-10Nb-5Ta alloys was studied. Increasing implantation dose from 1 × 1016N+/cm2to 2 × 1017N+/cm2leads to increase gradually both hardness and Young's modulus. The results show that implantation of 2 × 1017N+/cm2allowed to double the value of Young's modulus and to triple the value of hardness. Friction tests that have been conducted against 100Cr6 steel and alumina balls showed that tribological behavior of the two alloys depend on the nature of the counterpart material and is strongly affected by the implanted dose of nitrogen.

Modelling of the ion implantation modification of WC-Co indexable knives for wood machining

Modelling of the ion implantation modification of WC-Co indexable knives for wood machining. The paper presents the results of the modelling of nitrogen ion implantation parameters for W-C-Co material. Applications include the modification processes of WC-Co indexable knives for wood machining

Sequential nitrogen ion implantation in Si-based GaAs matrix and subsequent thermal annealing process: electrical characterization

Sequential nitrogen ion implantation in Si-based GaAs matrix and subsequent thermal annealing process: electrical characterization

Evolution of corrosion behavior for AA7075 aluminum alloy implanted with nitrogen

This work reports the corrosion behavior of the AA7075 aluminum alloy under two different tempers (T6 and T73) after nitrogen implantation in 0.5 mol·L−1 NaCl solution. A combination of Electrochemical Impedance Spectroscopy and surface microstructure characterization was used to analyze the effects of nitrogen implantation on corrosion resistance.Nitrogen implantation, at 2 × 1017 N+ ions·cm−2 and 50 keV energy, induces the formation of AlN layer improving the corrosion resistance of aluminum alloys as evidenced by initial corrosion tests and a less corroded area.The evolution of the impedance indicates that the corrosion improvement vanishes over time. Implanted and unimplanted alloys show similar electrochemical parameters after 20 h immersion. However, microscopic examination shows less corrosion damage for implanted alloys after 72 h of immersion. These findings suggest that the implantation only delays the onset of corrosion probably due to degradation of AlN layer in aqueous medium. The corrosion resistance at long periods only depends on the aging heat treatment applied to the AA7075 aluminum alloy and the effect of implantation is negligible.

Tuning the electrical properties of graphene oxide by nitrogen ion implantation: Implication for gas sensing

Tailoring the electrical properties of graphene oxide (GO) is one of the important requirements for its application in future electronic devices. A modified Hummer’s method was employed in the preparation of GO and spray coated on glass substrates, subsequently drying at 60 °C for 6 h. The as prepared samples were implanted with 100 keV nitrogen ions at the fluences of 1E15, 5E15 and 1E16 ions/cm2. A peak shift to higher 2θ in XRD pattern indicates the reduction of GO to rGO after N ion implantation. The intensity ratio of G and D bands (IG/ID) for GO derived from the Raman analysis increased from 0.97 to 1.02 after implantation (1E16 ions/cm2). The EDS analysis confirms the implantation of N ions in GO. The electrical conductivity improved as a function of fluence, and observed to be high for the sample of 1E16 ions/cm2, and is tested for methanol sensing. Concentration dependent methanol sensing shows 5.9% response for 300 ppm. Above results show that ion implantation is a promising method for controlled reduction of GO for tuning the electrical properties.

Образование дефектов в структурах GaAs с непокрытой и покрытой пленкой AlN поверхностями при имплантации ионов азота и последующем отжиге

AbstractThe concentration profiles of defects produced in structures upon the implantation of nitrogen ions into GaAs epitaxial layers with an uncovered surface and that covered with an AlN film and subsequent annealing are studied. The ion energies and the implantation doses are chosen so that the nitrogen-atom concentration profiles coincided in structures of both types. Rutherford proton backscattering spectra are measured in the random and channeling modes, and the concentration profiles of point defects formed are calculated for the samples under study. It is found that the implantation of nitrogen ions introduces nearly the same number of point defects into structures of both types, and the formation of an AlN film by ion-plasma sputtering is accompanied by the formation of an additional number of defects. However, the annealing of structures of both types leads to nearly the same concentrations of residual defects.

Effect of Nitrogen Ion Implantation on the Surface Hardness, Corrosion Rate, and Crystal Structure of Pure Aluminium

The weakness of aluminium and its alloys are relative low hardness and wear resistance. To improve this weakness a nitrogen ion implantation technique has been carried out. For the purpose, an ion implantation process was carried out for various of dose such as 0.578×1016 ion/cm2, 0.706×1016 ion/cm2, 0.842×1016 ion/cm2, 0.970×1016 ion/cm2, and 1.106×1016 ion/cm2 at a certain energy and beam current, 60 keV and 75 μA, respectively. Hardness test was performed using microhardness tester, the corrosion resistance was tested using the electrochemical method, and the crystal structure was analyzed using X-ray diffraction. From the hardness test result, it can be concluded that the optimum hardness in order of 37.5 VHN was achieved at an ion dose of 0.83×1017 ion/cm2. While the hardness for the untreated sample was 18.70 VHN. It meant, there is an increasing hardness by a factor of 100,53%. At these conditions, the corrosion rate reduces from 0.012 mmpy to 0.011 mmpy or reduce by a factor of 8.3%. Based on the XRD analysis, it can be obtained the AlN phase is formed through the peaks at 2-theta was 39.37° (111), 45.76° (200), and 66.88° (202).

Improving the functional properties of austenitic steels when modifying the surface with high-energy nitrogen ions

Abstract The work is devoted to the study of the influence of the implantation of nitrogen ions into the surface of austenitic corrosion-resistant steels in order to increase their functional properties, which is a relevant and significant task for practice. It has been established that irradiation of austenitic corrosion-resistant steels with nitrogen ions can be considered an effective way to increase hardness and the conditional yield strength in the operation of steels functioning in a corrosive environment.