Formation of amorphous carbon on the surface of poly(ethylene terephthalate) by helium plasma based ion implantation

The surface modification of poly(ethylene terephthalate) (PET) by helium plasma based ion implantation (He PBII) was studied. The effect of the main process parameters (acceleration voltage, fluence and fluence rate) on the alterations of the surface chemical composition and structure were investigated by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.According to SRIM calculations, at ion energies above 2 keV the stopping power of PET for He⁺ ions is dominated by the electronic component and the contribution of the nuclear component is relatively small. Degradation of the ester group and carbonisation were observed by XPS due to elimination of O-rich fragments. The total C-content of the modified layer increased with the increase of fluence rate and acceleration voltage of particles, enabling the purposeful alteration of the surface composition. A strong broadening was detected in the Raman spectrum between 1000 and 1700 cm⁻¹, testifying to the intense formation of amorphous carbon. The area ratio of the D (∼1410 cm⁻¹) to G (∼1570 cm⁻¹) band increased with the increase of particle fluence and the increase of acceleration voltage, offering the possibility of tailoring the chemical structure of the amorphous carbon layer created by the He PBII treatment.     

1.23 GeV Fe离子在C60薄膜中形成潜径迹的Raman谱分析

用能量为1.23GeV的快Fe离子辐照了多层堆叠的C60薄膜。用Raman散射技术分析了快Fe离子在C60薄膜中由强电子激发引起的效应，主要包括辐照引起C60分子的聚合及其高温、高压相（HTHP）的形成，和在高电子能损下C60晶体点阵位置上的C60分子向非晶碳的转变。由此演绎出了快Fe离子在C60薄膜中的损伤截面或潜径迹截面σ和潜径迹的半径心，及其随沉积在电子系统中的能量密度的变化而变化的规律。     

Effect of different ion beam energy on properties of amorphous carbon film fabricated by ion beam sputtering deposition (IBSD)

Amorphous carbon (a-C) films were fabricated by ion beam sputtering technique. The influence of sputtering ion beam energy on bonding structure, morphologic, mechanical properties, tribological properties and corrosion resistance of a-C films are investigated systematically. Morphology study shows that lowest surface roughness exists for mid-ion beam energy. Improved adhesion is observed for the films that are prepared under high ion beam energy, attributed to film graphitization, low residual stress and mixed interface. Relatively, a-C films prepared with ion beam energy of 2 keV exhibits optimum sp³ bond content, mechanical properties and corrosion resistance. It is found that the wear rate of DLC films decrease with increased ion beam energy in general, consistent with the varied trend of the H/E value which has been regarded as a suitable parameter for predicting wear resistance of the coatings. The correlation of the sp³ bond fraction in the films estimated from Raman spectroscopy with residual stress, nanohardness and corrosion resistance has been established.     

N+离子注入对锆-4合金耐腐蚀性能的影响

为了研究N+离子注入对锆-4合金耐腐蚀性能的影响,本文使用直线加速器产生的N+离子注入锆-4合金样品,通过对离子注入后样品电化学曲线的测量,分析不同剂量下N+离子注入对锆-4合金钝化电流密度的影响,同时使用透射电子显微镜分析注入层的微观结构.结果表明,随着注入剂量的提高(0-1×1016cm-2),样品钝化电流密度下降,耐腐蚀性能提高,其原因主要归结于样品表层由多晶结构到非晶结构的转变过程.     

Effect of pulse waveform on plasma sheath expansion in plasma-based ion implantation

In this paper, the effect of the pulse waveform on plasma sheath evolution around a diamond-shaped target has been simulated using fluid dynamic model in the context of plasma-based ion implantation (PBII). The implanted parameters of ions such as ion-implanted energy, impact angle and impact current have also been studied under different pulse shapes. Understandably, the longer pulse rise time would result in the lower ion impact energy, and less sheath expanding extent. By comparing the sheath structure under different pulse rise time, we found that long pulse rise time would enhance the conformation of the sheath to the target at the earlier stage of the pulse and would reduce the tendency of the ion depletion in the plasma sheath. Accordingly increase the ion impact current at the later stage of the pulse, which is quite important for the PBII process, when the ions have been accelerated adequately.     

Influence of nitrogen ion implantation energies on surface chemical bonding structure and mechanical properties of nitrogen-implanted silicon carbide ceramics

Nitrogen ions were implanted into silicon carbide ceramics (N⁺-implanted SiC) at different ions energies. The surface chemical bonding structure of N⁺-implanted SiC ceramics were investigated by using X-ray photoelectron spectroscopy (XPS). The hardness of N⁺-implanted SiC ceramics was measured using nano-indenter, and the friction and wear properties of the N⁺-implanted SiC/SiC tribopairs were studied using ball-on-disk type tribo-meter in water lubrication. The wear tracks were observed using non-contact surface profilometer and scanning electron microscope (SEM). The results showed that the surface roughness of N⁺-implanted SiC ceramic was higher than that of SiC ceramic, and some chemical bonds such as Si–N, C–C, CN and C–N bonds were formed in N⁺-implanted layer besides Si–C bonds. In comparison of SiC ceramic’s hardness, the hardness of N⁺-implanted SiC ceramics at 30 and 50 keV was higher while that at 65 keV was lower. Under water lubrication, the friction coefficient and the specific wear rates for the N⁺-implanted SiC/SiC tribopairs were all lower than those of the SiC/SiC tribopairs, and displayed the lowest values at 50 keV. According to XPS analysis, it was concluded that the high wear resistance and low friction coefficient for the N⁺-implanted SiC/SiC tribopairs were attributed to the formation of carbon rich composite on the surface of N⁺-implanted SiC ceramics.     

Structure and thermal stability of Au–Fe alloy nanoclusters formed by sequential ion implantation in silica

Sequential ion implantation of Au and Fe ions has been performed in silica. Despite the fact that the two species are not miscible in the bulk, structural characterizations show that the nanoparticles produced are a Au–Fe alloy. The crystalline structure of the nanoparticles is fcc with a lattice parameter of 0.395 nm. The nanocomposite is ferromagnetic at 3 K, with a magnetic moment per Fe atom equal to 1.4μ_B and it shows a hysteresis loop with a coercive field of 24 mTorr. Due to alloying, the optical absorption spectrum does not exhibit the typical surface plasmon resonance of gold nanoparticles. The sample exhibits a change of its optical and structural properties when is annealed at 600 °C.     

GCr15表面钽沉积及碳离子注入的摩擦性能的研究

GCr15钢广泛用于各类轴承制造.为提高其摩擦性能,用磁控溅射法在GCr15轴承钢试样表面沉积厚约100 nm的钽膜,再进行不同注量的50 keV碳离子注入.用Ф6的GCr15钢球做对磨试验,测试它们的摩擦性能,用SEM观察磨痕形貌.结果表明,处理后GCr15钢改性层的Ta2C含量随注量增加,摩擦性能得以提高.载荷1 N、滑动速度50 mm/s条件下,注入3×1017ions/cm2的试样耐磨性是原始试样的1.65倍;表面沉积钽膜后,摩擦系数由未处理前的0.8～1下降至0.5左右,钽膜注碳后摩擦系数更降至0.2～0.3,注入层主要以磨粒磨损为主.     

Effects of Li ion implantation energies on the structure, photoluminescence, and ferromagnetism properties of (Li, Co) co-implanted ZnO films

Room temperature ferromagnetism was observed in (Li, Co) co-implanted ZnO films. The implantation energy for Co ions was 400 keV, while for Li ions were 50, 100 and 200 keV, respectively. The ion implantation induced defects and disorder has been observed by the XRD, PL and TEM experiments. For the co-implanted ZnO films with Li ion implantation energies of 100 and 200 keV, the band energy emission disappears and the defect related emission with wavelength of 500-700 nm dominates, which can be attributed to defects introduced by implantation. Co-implanted ZnO Films with Li ion implantation energies of 200 keV show a saturation magnetization value (M_S) of over 9 × 10⁻⁵ emu and a positive coercive field of 60 Oe. The carrier concentration is not much improved after annealing and in the order of 10¹⁶ cm⁻³, which suggests that FM does not depend upon the presence of a significant carrier concentration. The origin of ferromagnetism behavior can be explained on the basis of electrons and defects that form bound magnetic polarons, which overlap to create a spin-split impurity band.     

镧离子注入对纯锆耐蚀性的影响

为了研究镧离子注入对纯锆耐蚀性的影响,样品表面分别注入了1×10~(16)-1×10~(17)cm-2的镧离子,使用MEVVA源作为注入源,注入能量为40 kv。X光电子谱(XPS)分析了注入样品表面镧的价态,三电极动电位扫描测定了注入样品在0.5 mol/L H2SO4溶液中的极化曲线,通过与空白样(未注入样品)比较可知,镧离子注入后,纯锆样品的耐蚀性大大提高。最后,讨论了耐蚀性提高的机理。     

N+注入对甘草幼苗部分耐旱特征效应的研究

植物幼苗主根、侧根及下胚轴的生长和根冠比值的大小是幼苗耐旱的重要特征.对甘草干种子注入能量为25 kev、注量为600×2.6×1013-3600×2.6×1013/cm2的N+,其中1800×2.6×1013/cm2的N+注入量能有效提高甘草6 d幼苗的主根生长和30 d幼苗根冠比干重和鲜重,促进侧根发生;也能明显刺激6 d和30 d幼苗的下胚轴和主根、茎高的生长.该参数可以作为沙漠化地区建立甘草植被发挥离子束注入当代效应的N+辐照的能量、注量的参考参数.在实验注入N+的参数范围内甘草幼苗耐旱特征的应答也表现出"损伤-修复-损伤"效应.     

低能Si~+离子注入聚丙烯薄膜对其结晶度及陷阱电荷的影响

本文介绍了低能Si~+离子注入聚丙烯薄膜对其结晶度、立构规整度以及陷阱电荷影响的一些研究结果。实验表明,在能量为55keV,剂量为3×10~(15)/cm~2的条件下对聚丙烯薄膜进行Si~+离子注入,通过TSC和红外光谱分析发现,材料的陷阱电荷得到大幅度下降。其红外结晶度及立构规整度均有明显的下降。因而,材料的短程螺旋结构增多,这些结构的变化将导致其特性发生变化。     

Optical properties of InxGa1−xP/InP grown at high fluence Ga implantation on InP using focused ion beam

Single-crystalline InP(1 0 0) substrate was implanted by 30 keV Ga⁺ ions with fluences of 1 × 10¹⁶-1.5 × 10¹⁷ cm⁻² followed by post-annealing treatment at 750 °C to recover implantation-induced structural defects and activate dopants into the lattices. The optical property, composition, and microstructure of the Ga⁺-implanted InP were studied by Raman spectroscopy and transmission electron microscopy (TEM). Raman spectra show that the In_xGa_1−xP phase is formed at a critical fluence of 7 × 10¹⁶ cm⁻². The newly grown phase was identified with the appearance of Ga rich TO_InP and In rich TO_GaP modes of a random alloy in the 1 bond-2 phonon mode configuration along with TEM structural identification.     

Synthesis and Characteristics of Diamond-like Carbon Films Deposited on Quartz Substrate

Diamond-like carbon (DLC) fihns are deposited on quartz substrate using pure CH4 in the surface wave plasma equipment. A direct current negative bias up to -90 V is applied to the substrate to investigate the bias effect on the film characteristics. Deposited films are characterized by Raman spectroscopy, infrared (IR) and ultraviolet-visible absorption techniques. There are two broad Raman peaks around 1340 cm^-1 and 1600 cm^-1 and the first one has a greater sp^3 component with an increased bias. Infrared spectroscopy has three sp^3 C-H modes at 2852 cm^-1, 2926 cm^-1 and 2962 cm^-1, respectively and also shows an intensity increase with the negative bias. Optical band gap is calculated from the ultraviolet-visible absorption spectroscopy and the increased values with negative bias and deposition time are obtained. After a thermal anneal at about 500℃ for an hour to the film deposited under the bias of-90 V, we get an almost unchanged Raman spectrum and a peak intensity-reduced IR signal, which indicates a reduced H-content in the film. Meanwhile the optical band gap changed from 0.85 eV to 1.5 eV.     

PVA和PEG对电子束辐照制备的Fe3O4纳米粒子的影响

常温常压下不加入任何催化剂，用两种不同的活性剂聚乙烯醇（Polyvinyl alcohol，PVA）和聚乙二醇（Polyethylene glycol，PEG），在水溶液中通过电子束辐照可以成功地制备纳米Fe3O4粒子。通过紫外可见光分光光度计（Ultraviolet-visible spectrophotometer，UV）、X射线衍射（x-ray diffraction）、透射电子显微镜（Transmission electron microscopy，TEM）对辐照后的样品的光学特性、结构、形貌、大小进行表征。发现不同的活性剂对纳米粒子的尺寸会产生影响。     

The Effects of Low-Energy Nitrogen Ion Implantation on Pollen Exine Substructure and Pollen Germination of Cedrus deodara

The aim of this study is to investigate the biological effects of ion beams on pollen. Pollen grains of Cedrus deodara were implanted with 30 keV nitrogen ion beams at doses ranging from 1 × 10^15 ions/cm^2 to 15 × 10^15 ions/cm^2. The effects of N^＋ implantation on the pollen exine substructure were examined using an atomic force microscope （AFM）, and the structure and morphology of pollen and pollen tubes were observed using a laser scanning confocal microscope （LSCM）. AFM observations distinctly revealed the erosion of the pollen exine caused by N^＋ implantation in the micrometer to nanometer range. Typical results showed that the erosion degree was linearly proportional to the ion dose. Pollen germination experiments in vitro indicated that N^＋ implantation within a certain dose range increased the rate of pollen germination. The main abnormal phenomena in pollen tubes were also analyzed. Our results suggest that low energy ion implantation with suitable energy and dosage can be used to break the pollen wall to induce a transfer of exogenous DNA into the pollen without any damage to the cytoplasm and nuclei of the pollen. The present study suggests that a combination of the method of ion-beam-induced gene transfer and the pollen-tube pathway method （PTPW） would be a new plant transformation method.     

Preparation of potassium iron(III) hexacyanoferrate(II) supported on activated carbon and Cs uptake performance of the adsorbent

Synthesis of potassium iron(III) hexacyanoferrate(II) (K/Fe-Fe(CN)₆) in the pores of activated carbon (AC) was attempted by impregnating AC with K₄[Fe(CN)₆] and FeCl₃, and the Cs uptake performance of the resulting adsorbent was examined. K/Fe-Fe(CN)₆ supported on AC was prepared by varying the reaction conditions such as the supplied amounts and molar ratios of the reagents, and the Cs uptake performance was optimized. The impregnated product was characterized by XRD, EPMA, and porosimetry to elucidate the condition to which Fe₄[Fe(CN)₆]₃ was filled in the AC pores. The K/Fe-Fe(CN)₆-on-AC was immersed in seawater containing 0.075 mmol · dm^?3 Cs and agitated for 1 day to obtain the Cs uptake. The Cs uptake was large at pH < 10 but decreased abruptly at pH > 10.5. The maximum Cs uptake was 10.4 μmol · g^?1 at the equilibrium Cs concentration of 49 μmol · dm^?3 and the distribution coefficient was 45.5 dm³ · g^?1 at the equilibrium concentration of 0.015 μmol · dm^?3, respectively. When K/Fe-Fe(CN)₆-on-AC was immersed in Cs-containing seawater, K⁺ ions in the adsorbent were completely exchanged for Na⁺ ions in seawater, and the added Cs⁺ ions were then substituted for the Na⁺ ions in the adsorbent.     

Influence of N2 flow rate on structure and properties of TiBCN films prepared by multi-cathodic arc ion plating and studied with ion beam scattering spectroscopy

TiBCN films were deposited on Si(100) and cemented carbide substrates by using multi-cathodic arc ion plating in C_2H_2 and N_2atmosp~here. Their structure and mechanical properties were studied systematically under different N_2 flow rates. The results showed that the Ti BCN films were adhered well to the substrates. Rutherford backscattering sp~ectroscopy was employed to determine the relative concentration of Ti, B, C and N in the films.The chemical bonding states of the films were explored by X-ray photoelectron sp~ectroscopy, revealing the presence of bonds of Ti N, Ti(C,N), BN, pure B, sp~2C–C and sp~3C–C, which changed with the N_2 flow rate. Ti BCN films contain nanocrystals of Ti N/Ti CN and Ti B_2/Ti(B,C)embedded in an amorphous matrix consisting of amorphous BN and carbon at N_2 flow rate of up to 250 sccm.     

Effect of nitrogen flow ratios on the microstructure and properties of (TiVCr)N coatings by reactive magnetic sputtering

The present paper reports the influence of growth conditions on the characteristics of (TiVCr)N coatings prepared by dc reactive magnetron sputtering at various N₂-to-total (N₂ + Ar) flow ratios, R_N. The crystal structures, microstructure, and mechanical, electrical and optical properties under the R_N were characterized. Results indicate that the TiVCr alloy and nitride coatings exhibited a single body-centered cubic type (BCC) and a face-centered cubic (FCC) solid solution structure, respectively. As the R_N increases, the preferred orientation (TiVCr)N coatings changed to (2 0 0). The grain size also had a significant increase. The microstructure of the coatings obviously changed from a porous to a compact and dense columnar structure. Accordingly, the physical properties of the coatings were improved due to the densification of the structure. The hardness of the (TiVCr)N was enhanced to about 15 GPa, and the electrical resistivity was lowered to 10,000 μΩ-cm.     

Effect of Ag and Li ion irradiation on superconducting Tl2Ca2Ba2Cu3O10 single crystals

The effect of irradiation by 50 MeV Li³⁺ and 200 MeV Ag¹⁵⁺ ions on single crystals of Tl₂Ca₂Ba₂Cu₃O₁₀ (Tl2223) superconductor has been investigated at different fluences. Isothermal magnetization hysteresis loops have been recorded at different temperatures using a SQUID magnetometer and the effect of irradiation on the critical current density, irreversible field, second magnetization peak and pinning force has been studied. Irradiation by 200 MeV Ag¹⁵⁺ ions resulted in increased hysteresis and irreversibility field while no change in second magnetization peak position and critical temperature was observed. A broadening in the hysteresis loop before the second magnetization peak was also observed for the crystals irradiated by Li³⁺ ions. Annealing of irradiated crystals at 500 °C resulted in reduction of point defects created by Li³⁺ ions.