Effect of Nitrogen Ion Implantation on Microstructure and Improvement of Titanium Corrosion Resistance

In the present study the effect of nitrogen ion implantation on the structure of titanium surface and corrosion resistance have been investigated. In this experiment 30 keV nitrogen ion beam of 1 × 10¹⁸ to 5 × 10¹⁸ ions/cm² fluence was used. Crystalline structure of the different samples was studied by X-ray diffraction analysis. The roughness variations before and after implantation were observed by atomic force microscopy. The corrosion test was used to compare the corrosion resistance of titanium before and after ion implantation. The surface morphology of the samples after corrosion test was investigated by scanning electron microscopy. The results showed that nitrogen ion implantation has a substantial effect on the improvement of titanium resistance against corrosion.     

Effect of Nitrogen Ion Implantation in Copper

In this study, copper samples with 99% purity implanted by N⁺ and N₂ ⁺ ions. Implantation of ions performed at 50 keV and various doses ranging from 1 × 10¹⁷ to 1 × 10¹⁸ ions/cm². Morphology of samples’ surface studied by atomic force microscopy. Microstructure of modified surfaces after ion implantation obtained using grazing incidence X-ray diffraction technique (GIXRD). Formation of both copper nitride and copper trinities confirmed by GIXRD results. Microhardness properties and corrosion behavior of implanted samples measured by Vickers and corrosion test, respectively. The maximum hardness of copper surface observed after nitrogen ion implantation at the dose of 3 × 10¹⁷ ions/cm². Moreover, the results showed that corrosion resistivity significantly increase.     

Microstructure and Surface Properties of Silver after High Dose Nitrogen Ion Implantation

In this paper the effect of nitrogen ion implantation at the energy of 50 keV and doses in the range between 10¹⁷ and 2 × 10¹⁸ ions/cm² on silver surface has been discussed. X-ray diffraction (XRD) analysis was used to characterize microstructure of implanted layer. The XRD results confirmed that by such implantation AgN₃ has been produced. Silver trinitride with orthorhombic structure was formed on cubic structure of silver surface. RMS roughness of implanted samples have been obtained using atomic force microscopy (AFM) analysis and compared with un-implanted sample. Microhardness properties of implanted samples measured by Vickers test. The results show that by increasing the ion dose up to 1 × 10¹⁸ ions/cm² hardness enhances. Finally, reflection changes at the UV–Vis-NIR region measured by diffuse reflectance accessory of a spectrophotometer. The results of spectrophotometry analysis show reduction in diffused reflection spectrum of nitrogen implanted samples.     

Ti离子注入SiO_2合成TiO_2纳米颗粒及其光学性质

将105 keV的Ti离子注入到SiO_2玻璃至1×10~(17)、2×10~(17) cm~(-2),并在氧气气氛下进行热处理,借助紫外可见分光光度计、掠入射X射线衍射光谱仪、透射电子显微镜、原子力显微镜等多种测试仪器,详细研究了Ti O2纳米颗粒的形成、结构、分布及其光吸收和催化性能。研究结果表明,高注量Ti离子注入结合氧气气氛热处理可以在SiO_2基底中形成TiO_2纳米颗粒,并以金红石相为主。合成的TiO_2纳米颗粒的形貌明显依赖于离子的注量,随离子注量增加,形状不规则且分散排列的TiO_2纳米颗粒会转变成尺寸较为均匀、分布致密的纳米颗粒,进而形成了TiO_2类颗粒膜结构。另外,光催化降解实验结果表明,合成的纳米颗粒对罗丹明B溶液具有一定的降解作用。     

Oxygen Ion Implantation into Indium Phosphate

This paper is the results of oxygen ion implantation on morphological and electrical properties of indium phosphate (InP) semiconductor wafers. The oxygen ions were implanted at 30 keV and various doses in the range between 5 × 10¹⁵ and 5 × 10¹⁷ ions/cm² and at nearly room temperature. The changes in surface roughness and resistivity before and after the implantation is studied using atomic force microscopy (AFM) and four-point probes technique, respectively. The results show that the resistivity is depend on the ion implantation dose. In addition, the RMS roughness of implanted samples dramatically increases by accumulation of oxygen ion dose.     

Effect of CH<Subscript>4</Subscript> Ion Implantation in Pure Aluminium

In this paper, aluminium samples with 99.96% purity were exposed to ion beam, extracted from CH₄ plasma. Implantation of ions were performed for 50 keV energy and various doses ranging from 1 × 10¹⁷ to 6 × 10¹⁷ ions/cm². Morphology of surfaces, roughness and its evolution during variation of ion dose has been studied by atomic force microscopy (AFM). Microstructure of the modified surfaces after ion implantation has been obtained by X-ray diffraction technique and Raman spectroscopy. Formation of aluminium carbide (Al₄C₃) was confirmed by XRD results at implantation doses of 3 × 10¹⁷ and 6 × 10¹⁷ ions/cm². In addition, it was observed that when the ion dose is increased, orientation of aluminium planes change from (2 2 0) to (2 0 0). Corrosion test was performed and compared for implanted and un-implanted samples. The results showed that corrosion resistivity increase by accumulation of ion dose.     

低束流钕离子注入外延硅薄层的结构研究

采用金属蒸气真空弧(MEWA)离子源以低束流方式将Nd离子注入到外延硅片中，经高温快速退火处理，制备了结晶良好的钕硅掺杂层。用扫描电子显微镜(SEM)、反射式高能电子衍射(RHEED)和X射线衍射(XRD)分析了在不同退火条件下样品注入层相结构的变化。研究结果表明，经高温热处理，注入层形成结晶良好的钕硅化合物，出现由Nd5Si4相向NdSi相转变的趋势。并对其转变过程进行了初步探讨。     

Features of Zr-rich corner of the Zr-N-O ternary system by controlled low-pressure oxidation and thermodynamic analysis

In order to clarify the Zr-rich corner of the Zr-N-O ternary system, a series of nitridation and controlled low-pressure oxidation heatings were made on zirconium metal plates. The experiments were made in separated reaction sequences, which were (1) oxidation of pre-nitrided zirconium, and (2) simultaneous nitridation and oxidation of zirconium. Low-partial pressures of oxygen were obtained by using a redox couple of either Mo/MoO₂ or Cu₂O/CuO. The samples were characterized by X-ray diffraction, optical microscopy, and electron probe micro analysis. Experimental results were coupled with a preliminary thermodynamic analysis with a sublattice formalism to draw a provisional ternary isotherm at 1373 K.     

Evaluating zirconium–zirconium hydride interfacial strains by nano-beam electron diffraction

Nano-beam electron diffraction has been used to quantify the elastic strain field associated with δ-hydride needles embedded in an α-Zr matrix. It has been found that the volume misfit associated with precipitation results in elastic strains that are ～4× greater in the matrix than the hydride. Electron energy loss spectroscopy was used to detect hydrogen enrichment at the matrix–hydride interface by a shift in the zirconium plasmon peak. This work highlights that γ-hydride is metastable and acts as a precursor to equilibrium δ-hydride and that compositional variations within the hydride can be detected using electron energy loss spectroscopy.     

Microwave Plasma Chemical Vapor Deposition of Diamond Films on Silicon From Ethanol and Hydrogen

Diamond films with very smooth surface and good optical quality have been deposited onto silicon substrate using microwave plasma chemical vapor deposition(MPCVD)from a gas mixture of ethanol and hydrogen at a low substrate temperature of 450℃.The effects of the substrate temperature on the diamond nucleation and the morphology of the diamond film have been investigated and observed with scanning electron microscopy(SEM).The microstructure and the phase of the film have been characterized using Raman spectroscopy and X-ray diffraction(XRD).The diamond nucleation density significantly decreases with the increasing of the substrate temperature.There are only sparse nuclei when the substrate temperature is higher than 800℃ although the ethanol concentration in hydrogen is very high.That the characteristic diamond peak in the Raman spectrum of a diamond film prepared at a low substrate temperature of 450℃ extends into broadban indicates that the film is of nanophase.No graphite peak appeared in the XRD pattern confirms that the film is mainly composed of SP^3 carbon.The diamond peak in the XRD pattern also broadens due to the nanocrystalline of the film.     

Transmission electron microscopy of αZrO2 films formed in 573 K oxygen

Oxide films between 10 and 362 nm thickness were removed from zirconium substrates and examined by selected area electron diffraction and transmission electron microscopy. Evidence was found for a dynamic process of oxide crystallite nucleation, recrystallization and growth. Investigations were limited to oxide film thicknesses of less than 365 nm due to the presence of a dense network of amorphous oxide protusions at the oxide/metal interface.     

A metallographic study of the terminal solubility of hydrogen in zirconium at low hydrogen concentrations

The terminal solid solubility of hydrogen in alpha zirconium has been investigated using optical metallographic techniques. Hydrogen concentrations from 4 to 230 mg/kg were studied and good agreement found with previous determinations at concentrations above 25 mg/kg. Based on electron microscopic analysis of the hydrides, the solvus measured at hydrogen concentrations less than 25 mg/kg was determined to be that for the gamma hydride phase. From a least-squares fit of the data, the terminal solid solubility of this phase is given by the expression 3.43 × 10⁴ exp(?32200/RD) mg/kg.     

Atomic layer deposition of copper thin film and feasibility of deposition on inner walls of waveguides

Copper thin films were deposited by plasma-enhanced atomic layer deposition at low temperature, using copper(I)-N,N′-di-sec-butylacetamidinate as a precursor and hydrogen as a reductive gas. The influence of temperature, plasma power, mode of plasma, and pulse time, on the deposition rate of copper thin film, the purity of the film and the step coverage were studied.The feasibility of copper film deposition on the inner wall of a carbon fibre reinforced plastic waveguide with high aspect ratio was also studied. The morphology and composition of the thin film were studied by atomic force microscopy and x-ray photoelectron spectroscopy,respectively. The square resistance of the thin film was also tested by a four-probe technique. On the basis of on-line diagnosis, a growth mechanism of copper thin film was put forward, and it was considered that surface functional group played an important role in the process of nucleation and in determining the properties of thin films. A high density of plasma and high free-radical content were helpful for the deposition of copper thin films.     

H、He离子辐照对国产ZIRLO合金氧化膜的影响

针对国产ZIRLO合金开展了H、He离子辐照对其腐蚀性能影响的研究。对国产ZIRLO合金样品分别进行高温（300 ℃）H、He离子辐照试验，辐照峰值剂量为1 dpa，之后进行模拟一回路腐蚀试验。通过腐蚀增重方法得到腐蚀动力学曲线。利用慢正电子湮没多普勒展宽谱对未辐照样品和辐照样品进行微观结构表征，用透射电子显微镜对腐蚀125 d的样品进行微观结构表征。结果表明，H、He离子辐照并未改变ZIRLO合金的腐蚀机理。He离子辐照产生的空位团可促进腐蚀过程中裂纹形核，增加了氧扩散通道，减少氧扩散激活能，导致腐蚀初期有明显的加速效应。H离子辐照对腐蚀的加速现象不如He离子辐照明显，原因是H离子辐照产生H-空位复合缺陷对氧扩散激活能减少作用较小。     

Structure of ion tracks in ceria irradiated with high energy xenon ions

Structure and accumulation behavior of ion tracks in CeO₂ irradiated with 200 MeV Xe ions were examined by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) to obtain fundamental knowledge on the microstructure evolution induced by fission fragments in nuclear fuels and transmutation targets, which is of importance for the development of advanced fuel/target materials at high burn-up conditions. Bright-field (BF) TEM images of ion tracks from an inclined direction showed Fresnel contrast along penetrating path of incident ions. The signal intensity of high-angle annular dark-field (HAADF) STEM images was decreased at the core damage region of ion tracks along the path of ions, revealing the reduction of atomic density inside the ion track. Preferential formation of smaller and larger ion tracks was observed at a high ion fluence of 1 × 10¹⁴ cm⁻² compared to a low ion fluence of 1 × 10¹¹ cm⁻². Results were discussed due to the coalescences and incomplete recovery of the core damage regions during the overlap of high density electronic excitation damage, which is induced during the repetition of the formation and recovery of ion tracks within an influence region.     

Adhesion Improvement of Zirconium Coating on Polyurethane Modified by Plasmas

In order to improve the adhesion of the middle frequency magnetic sputtered zirconium coating on a polyurethane film,an anode layer source was used to pretreat the polyurethane film with nitrogen and oxygen ions.SEMs and AFM roughness profiles of treated samples and the contrast groups were obtained.Besides,XPS survey spectrums and high resolution spectrums were also investigated.The adhesion test revealed that ion bombardment could improve the adhesion to the polyurethane coating substrate.A better etching result of oxygen ions versus nitrogen predicts a higher bonding strength of zirconium coating on polyurethane and,indeed,the highest bonding strengths are for oxygen ion bombardment upto 13.3 MPa.As demonstrated in X-ray photoelectron spectroscopy,the oxygen ion also helps to introduce more active groups,and,therefore,it achieves a high value of adhesion strength.     

An in-situ study of the dissolution of γ-zirconium hydride in zirconium

The dissolution of γ-zirconium hydride has been examined in single crystal specimens of zirconium using a hot stage in a high voltage electron microscope. It was found that a significant proportion of the dislocations generated by the hydride needles during growth were not annihilated when dissolution occurred on heating to well above the solvus temperature. This is contrary to earlier work where similar experiments were carried out with thinner specimens at conventional accelerating voltages. Electron irradiation completely prevented annihilation of the hydride dislocations during dissolution. The results are discussed in relation to (a) repeated nucleation at the same sites during thermal cycling, (b) external shape changes (growth), (c) strain steps observed during thermal cycling under creep conditions, (d) positron annihilation experiments, and (e) the terminal solid solubility of hydrogen in zirconium.     

CrN films deposited by ion source-assisted magnetron sputtering

CrN coatings were deposited on Si(100) and piston rings by ion source assisted 40 kHz magnetron sputtering.Structure and composition of the coatings were characterized by X-ray diffraction,atomic force microscopy,scanning electron microscopy and transmission electron microscopy.Mechanical and tribological properties were assessed by microhardness and pin-on-disc testing.The ion source-assisted system has a deposition rate of 3.88 μm/h,against 2.2 μm/h without ion-source assistance.The CrN coatings prepared with ion source assistance exhibited an increase in microhardness(up to 16.3 GPa) and decrease in friction coefficient(down to 0.48) at the optimized cathode source-to-substrate distance.Under optimized conditions,CrN coatings were deposited on piston rings,with a thickness of 25 μm and hardness of 17.85 GPa.     

Thermal annealing behavior of hydrogen and surface topography of H2+ ion implanted tungsten

Tungsten (W) has been proposed as a plasma-facing material in fusion reactors due to its outstanding properties. Degradation of the material properties is expected to occur as a result of hydrogen (H) isotope permeation and trapping in W. In this study, two polycrystalline W plates were implanted with 80 keV H₂⁺ ions to a fluence of 2 × 10²¹ H⁺/m² at room temperature (RT). Time-of-flight secondary ion mass spectrometry (ToF-SIMS), focused ion beam (FIB), and scanning electron microscopy (SEM) were used for sample characterization. The SIMS data shows that H atoms are distributed well beyond the ion projected range. Isochronal annealing appears to suggest two H release stages that might be associated with the reported activation energies. H release at RT was observed between days 10 and 70 following ion implantation, and the level was maintained over the next 60 days. In addition, FIB/SEM results exhibit H₂ blister formation near the surface of the as-implanted W. The blister distribution remains unchanged after thermal annealing up to 600 ?C.     

Surface analytical studies of ion-implanted uni-directionally aligned silicon nitride for tribological applications

Uni-directionally aligned silicon nitride, which exhibits both high strength and high toughness, was implanted with B⁺, N⁺, Si⁺ and Ti⁺ ions at a fluence of 2 × 10¹⁷ ions/cm² and an energy of 200 keV. The effect of ion implantation on the surface structure of the uni-directionally aligned silicon nitride has been studied, in terms of surface analyses such as atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS) and X-ray absorption near edge structure (XANES). It was clarified that the ion-implanted layer was amorphized and the implantation profile showed good agreement with that estimated from a TRIM simulation. It was found that BN and TiN were formed in B⁺- and Ti⁺-implanted Si₃N₄, respectively. There was a slight difference in ion implantation depth among different structures of Si₃N₄, considered to be due to differences in ion channeling.