Deposition of nanocomposite CNx/SiO2 films in inductively coupled r.f. discharge

Hard films were deposited in an inductively coupled r.f. discharge at a frequency of 3.5 MHz by the chemical transport of carbon from a graphite target in a nitrogen atmosphere combined with evaporation from a quartz tube. The nitrogen flow was varied from 1.0 to 4.0 sccm. The r.f. power supplied was in the range 2.5–3.5 kW. Silicon substrates were placed on the graphite holder whose temperature was 700–800°C. In the emission spectra the CN, N₂ and C₂ molecular bands and the silicon, carbon, oxygen and nitrogen atomic lines were observed. The ratio of nitrogen to carbon in the films ranged from 0.1 to 0.55 while the ratio of oxygen to silicon was about 2 for all the films studied. The films had a maximum hardness of 35 GPa and they showed a high elasticity up to 88%, good fracture toughness and adhesion to the substrate. Unlike carbon nitride films the CN_x/SiO₂ films were almost non-absorbing in the visible range.     

Flow and temperature patterns in an inductively coupled plasma reactor: Experimental measurements and CFD simulations

Measurements of temperature patterns in an inductively coupled plasma (ICP) have been carried out experimentally. Plasma torch was operated at different RF powers in the range of 3–14 kW at near atmospheric pressure and over a wide range of sheath gas flow rate (3–25 lpm). Measurements were made at five different axial positions in ICP torch. The chordal intensities were converted into a radial intensity profile by Abel Inversion technique. Typical radial temperature profile shows an off‐axis temperature peak, which shifts toward the wall as the power increases. Temperatures in the range of 6000–14,000 K were recorded by this method. The temperature profiles in the plasma reactor were simulated using computational fluid dynamics (CFD). A good agreement was found between the CFD predictions of the flow and temperature pattern with those published in the literature as well as the temperature profiles measured in the present work. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3647–3664, 2014     

Optical and electrical properties of a-C:H deposited by magnetic confinement of r.f. PECVD plasma

Amorphous hydrogenated carbon (a-C:H) thin films have been deposited in an r.f. PECVD chamber using a magnetic multipole system to confine the plasma. The influence of magnetic field on both the plasma parameters and the film properties has been studied. The results are compared with those obtained under similar conditions using a standard PECVD system. Optical emission spectroscopy (OES) shows an increase in the intensity of the hydrogen and C–H lines in the plasma. EELS, optical, electrical and electron field emission measurements have been used to characterize the deposited films. The sp³/sp² ratio was increased using the magnetic field and the optical gap was also increased as compared to films grown using a standard process. The electron field emission was found to be improved (higher current density and smaller barrier height) for samples deposited in the presence of the magnetic field.     

Inductively coupled r.f. plasma assisted chemical vapour deposition of diamond-like carbon coatings

A 13.56 MHz magnetically confined inductively coupled plasma (ICP) system has been applied to deposit diamond-like carbon (DLC) coatings from a methane plasma. An important advantage of using a remote plasma source over the conventional capacitively coupled parallel plate system is the possibility of decoupling the discharge power absorption and the substrate bias, allowing independent control of ion flux and energy. Five deposition parameters have been varied: the bias voltage, the r.f. power in the ICP source, the methane flow, the distance between the source and the substrate, and the cooling of the substrates. The mechanical properties of the coatings (hardness and Young's modulus) were measured by nano-indentation. The structural properties were determined by Fourier transform infrared spectroscopy and Raman spectroscopy. In addition, mass spectrometry was performed to determine the degree of dissociation of the precursor gas in the plasma. An efficient cooling of the substrates was very important to obtain higher deposition rates and slightly better quality of the coatings. It was demonstrated that the deposition rate can be substantially raised compared with the conventional capacitively coupled system, without reducing the quality of the coatings. A disadvantage of the ICP technique is the fraction of capacitive coupling from the r.f. coil to the plasma, which causes sputtering of the dielectric window resulting in contamination of the coatings and deterioration of their properties. This problem was reduced by installing a Faraday shield between the coil and the dielectric window.     

电感耦合等离子体的维护与保养

总结了在测定微量金属离子过程中对电感耦合等离子体发射光谱仪的使用、维护和保养,以延长仪器的使用寿命,减少易损件的消耗.     

Study on flow fields of centrally fuel rich swirl burner and its applications

Experiments on a single-phase test facility were done to optimize primary air outlet cones of a centrally fuel rich swirl coal combustion burner. On the basis of optimized results from the single-phase test, a three-component particle-dynamics anemometer was used to measure, in the near-burner region, the characteristics of gas/particle two-phase flows for the burner with two primary air outlet cones, on a gas/particle two-phase test facility. Velocities, RMS velocities and particle volume flux profiles were obtained. According to the results, the primary air outlet cone structure of the centrally fuel rich burner was matching a 670 ton per hour boiler. The performance of the burner on a 670 ton per hour boiler was studied.     

电感耦合等离子光谱法测定氢氧化钠中金属离子

应用电感耦合等离子发射光谱仪（ICP）测定氢氧化钠中三氧化二铁，二氧化硅，氧化钙，铜。该法比国标测定方法更加简便，快速，并有较高的精密度和准确度。     

土壤中微量元素的电感耦合等离子体质谱分析

建立了一种电感耦合等离子体质谱法测定土壤中微量元素的方法。利用该方法分析了标准物质(GBW 07401)中微量元素,其结果与标准值一致。该方法用于分析土壤样品中的微量元素,得到令人满意的结果。     

Effect of sulfur hexafluoride gas and post-annealing treatment for inductively coupled plasma etched barium titanate thin films

Aerosol deposition- (AD) derived barium titanate (BTO) micropatterns are etched via SF₆/O₂/Ar plasmas using inductively coupled plasma (ICP) etching technology. The reaction mechanisms of the sulfur hexafluoride on BTO thin films and the effects of annealing treatment are verified through X-ray photoelectron spectroscopy (XPS) analysis, which confirms the accumulation of reaction products on the etched surface due to the low volatility of the reaction products, such as Ba and Ti fluorides, and these residues could be completely removed by the post-annealing treatment. The exact peak positions and chemicals shifts of Ba 3d, Ti 2p, O 1 s, and F 1 s are deduced by fitting the XPS narrow-scan spectra on as-deposited, etched, and post-annealed BTO surfaces. Compared to the as-deposited BTOs, the etched Ba 3d_5/2, Ba 3d_3/2, Ti 2p_3/2, Ti 2p_1/2, and O 1 s peaks shift towards higher binding energy regions by amounts of 0.55, 0.45, 0.4, 0.35, and 0.85 eV, respectively. A comparison of the as-deposited film with the post-annealed film after etching revealed that there are no significant differences in the fitted XPS narrow-scan spectra except for the slight chemical shift in the O 1 s peak due to the oxygen vacancy compensation in O₂-excessive atmosphere. It is inferred that the electrical properties of the etched BTO film can be restored by post-annealing treatment after the etching process. Moreover, the relative permittivity and loss tangent of the post-annealed BTO thin films are remarkably improved by 232% and 2,695%, respectively.     

Neural network modelling of the inductively coupled RF plasma synthesis of silicon nanoparticles

The synthesis of silicon nanopowders by an inductively coupled plasma (ICP) process is investigated. The specific surface area (SSA) of the elaborated particles is determined by nitrogen absorption (BET) as a function of the quenching gas flow rate and the precursor feeding rate. Nanopowders with specific surface areas varying from 69 to 194 m² g^− 1, corresponding to equivalent particle sizes of 37 and 13 nm respectively, could be produced. The correlation between these two input parameters and the output SSA has been numerically modelled with linear regression and artificial neural networks approaches. It has been demonstrated that with the available data set, a regression model with quadratic regressors and a neural network modelling give a similar response.     

The plasma polymerization of vinyl monomers. I. The design,construction, and operation of an inductively coupled plasma generator and preliminary studies with nine monomers

An apparatus was constructed which would allow vinyl-type monomers (and others) to polymerize at ambient temperatures in the presence of an inductively coupled RF field. The details of the construction of the system are reported along with preliminary results obtained from nine monomers: styrene, methylvinyldichlorosilane, vinyl acetate, acrylonitrile, vinyl fluoride, 1,1-difluoroethylene, vinyl chloride, ethylene, and 1,3-butadiene.     

Indiscriminate revelation of dislocations in single crystal SiC by inductively coupled plasma etching

To reveal dislocations in SiC wafers, conventionally, molten KOH etching method has been widely used. However, when highly doped sites exist on the wafer, the molten KOH etching method is not applicable owing to the enhanced isotropic electrochemical etching phenomenon. In this study, plasma etching is first applied to reveal dislocations in a 4H-SiC wafer with both highly doped and lightly doped areas. The mechanisms of dislocation revelation by dry etching have been theoretically analyzed and it has been revealed that the dislocation revelation ability of dry etching is highly related to the temperature of the etching process. The results demonstrate that inductively coupled plasma (ICP) etching can maintain its effectiveness for dislocation revelation of SiC wafers regardless of the doping concentrations. This work offers an alternative approach to indiscriminately and accurately reveal dislocations in SiC wafers.     

电感耦合等离子体质谱法分析小麦中的稀土元素

为了研究稀土元素在小麦中的分布,建立了一种压力密闭消解电感耦合等离子体质谱分析Y、La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb和Lu等15种稀土元素的方法。该方法被用于分析国际柑橘叶标准物质(NIST 1572)中的稀土元素,结果与标准值一致。该方法被用于研究稀土元素在小麦中的分布,稀土元素在小麦中的含量整体上遵循如下的顺序:麦粒<麦茎<麦壳<麦叶<麦根。     

Automation of a flow injection system for the determination of dissolved silver at picomolar concentrations in seawater with inductively coupled plasma mass spectrometry

An automated flow injection system for the determination of dissolved silver at ultratrace concentrations in seawater, and controlled under LabVIEWtrade mark, is described. The flow injection system allows online processing of seawater samples before their analysis using a magnetic sector inductively coupled plasma mass spectrometry (MS-ICP-MS) instrument. Samples were analysed with a minimum amount of manipulation, thereby reducing the risk of contamination. In addition, the flow injection approach with incorporation of an anion exchange minicolumn allowed ready removal of analytical interferences caused by the saline matrix. The software allowed full control of all flow injection components (valves and pumps) and removed manual time control and, therefore, operator errors. The optimized system was capable of five sample injections per h, including preconcentration and wash steps. The limit of detection was 0.5 pM for a 240-s sample load time, which allowed the determination of dissolved silver in open ocean waters, where picomolar concentration levels are typically encountered.     

Effect of primary air flow types on particle distributions in the near swirl burner region

A three-component particle-dynamics anemometry is used to measure, in the near-burner region, the characteristics of gas-particle two phase flows with two swirl burners with different primary air flow types, on a gas-particle two phase test facility. One burner is the radial bias combustion swirl pulverized coal burner whose primary air is non-swirl, and the other is the swirl burner whose primary air is swirl. With the former one, particle volume fluxes, particle volume fractions and particle number concentrations are bigger near the edge of central recirculation zone, and the particle volume fractions and the particle number concentrations are also bigger in the central recirculation zone. With the latter one, the particle volume fluxes and particle number concentrations are less near the edge of the central recirculation zone, and they are bigger in the wall zone. The influence of gas-particle flow characteristics on combustion has been analyzed, and the theory of air-surrounding-coal combustion is given.     

电感耦合等离子体原子发射光谱法测定铝铁合金中的硅、磷

建立了铝铁合金中硅、磷元素的电感耦合等离子体原子发射光谱(ICP-AES)的测定方法,样品经盐酸、硝酸溶解,曲线采用基体匹配,于优化选定的仪器条件下测定硅、磷元素。本方法测定回收率均在96.0%~98.0%之间,标准偏差小于0.8%,该法操作简便,分析快速,结果准确。     

Structure of the solid pyrolysis products produced from propylene in a low-pressure inductive r.f. plasma

The morphology, homogeneity, density, composition and crystallographic structure of the two different forms of pyrocarbon (PyC) deposited in a low pressure inductive r.f. plasma from propylene and argon mixtures, were studied. The low density (1.1–1.5 g · cm⁻³) PyC deposits on the reactor walls mainly at low gas pressures (2.5 Torr) and is amorphous. The second, denser (1.80–2.15 g · cm⁻³) form deposits only on the grounded solid substrate. It consists of soft and dense components and its structure was identified by X-ray diffraction as imperfect hexagonal. Optical studies of the surface texture of the dense PyC show an “orange peel”-like structure (monticules). The mean size of the monticules and their homogeneity are affected by the gas pressure in the reactor.     

食醋中多种微量元素的快速质谱分析

建立了微波消解-高分辨电感耦合等离子体质谱法(HR-ICP-MS),同时测定食醋中Na、Mg、P、K、Ca、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Sr、Mo、Cd、Sn、Sb、Ba、Hg、Pb等22种微量元素的方法。样品用HNO3+H2O2经微波消解并进一步用超纯水稀释后,直接用HR-ICP-MS同时测定上述微量元素。采用低分辨模式和中分辨模式有效地消除了多原子离子对待测元素的干扰,以Sc、In、Re为内标元素可明显改善长时间测定的稳定性和精密度水平。结果表明,各元素的检出限在0.001～2.511μg/L之间,加标回收率在90.00%～107.00%之间,相对标准偏差(RSD)<3.26%。     

电感耦合等离子体发射光谱法检测一次性纸杯中微量元素

建立了同时测定一次性纸杯中Cu,Mn,Fe,Zn,K,Mg,Ca,Cr,Hg和Pb等10种微量元素的电感耦合等离子体发射光谱(ICP-OES)法。实验结果表明:方法线性关系良好,相关系数在0.991~0.999之间,线性范围较宽,操作简便。采用该法对10种品牌一次性纸杯(无油墨部分)中微量元素进行检测表明:无油墨部分的纸杯中含有丰富的K,Mg和Ca等有用元素,同时也含有Zn和Fe等人体必需的微量元素;Cu,Mn,Fe,Zn和K质量浓度分别为1.02~24.15,0.003~2.77,9.16~52.56,0.39~1.62和2.17~15.91 mg/L;品牌3,5和7纸杯含有Pb;品牌3,4和5纸杯含有Hg;品牌7纸杯Cr和Cu含量最高。