离子束辅助磁控溅射沉积铬-铜-氮薄膜的结构与性能

应用低能离子束辅助磁控溅射（IBAMS）沉积铬-铜-氮薄膜,研究了铜含量和轰击能量对薄膜结构、硬度和断裂韧度的影响。结果表明：在相同的轰击能量（400eV）下,铜含量对薄膜结构和硬度的影响不明显,但是铜的加入有利于提高薄膜的断裂韧度;离子辅助轰击能量从400eV增加到800eV时薄膜的结构发生了显著变化,断裂韧度和硬度均大幅度提高。     

离子束辅助真空电弧沉积Zr-Ni-N薄膜的研究

采用多弧离子镀技术在高速钢和单晶硅基体上制备Zr-Ni-N复合薄膜,研究了低能氮离子束对Zr-Ni-N涂层结构、表面形貌和硬度的影响。研究表明:用低能氮离子束辅助真空电弧沉积Zr-Ni-N膜,ZrN结构在(111)晶面出现一定的择优取向,并对Zr-Ni-N膜层有一定的强化作用,膜层表现出较高的显微硬度。     

溶液法高质量外延薄膜助力新型复杂氧化物研究

目前普遍用于外延薄膜生长的物理气相沉积技术在复杂氧化物外延薄膜制备工艺,存在工艺探索周期长、生长窗口窄、参数稳定性低等困难。为此,中国科学院深圳先进技术研究院李江宇教授课题组,发展了适用于(1-x)BiTi(1-y)/2 FeyMg(1-y)/2 O3-(x)CaTiO3(BTFM-CTO)体系室温多铁固溶体的溶液法大面积外延薄膜制备工艺。该工作充分体现了溶胶凝胶法简单快速、成本低廉、成分调控均匀灵活等特点,在复杂氧化物外延薄膜研究及应用方面展现出巨大的潜力和优势,并易于与工业生产相结合,助力提升新型复杂氧化物材料器件化的发展速度。     

RLVIP技术制备Ge1-xCx薄膜的X射线光电子能谱

应用低压反应离子镀(RLVIP)技术在Ge基底上沉积了Get1-xCx薄膜.制备过程中,低压等离子源作为辅助等离子源,Ge作为蒸发材料,CH4作为反应气体,在相同的沉积条件下以不同的沉积速率制备了C含量(x)从0.23到0.78的Ge1-xCx薄膜.X射线衍射测试表明制备的Ge1-xCx薄膜为无定形结构.用X射线光电子能谱研究了不同C含量下Ce1-xCx薄膜中C的化学键合变化.研究结果表明;当x>0.78时,成键为C-H键;当x为0.53～0.62时,成键为C-C键;当x<0.47时,成键为Ge-C键.     

中国科学家成功研制超平整石墨烯薄膜

南京大学物理学院高力波教授团队将质子辅助生长用于高质量石墨烯的制备,成功研制出超平整石墨烯薄膜。该研究工作不仅探索出了一种可控生长超平整石墨烯薄膜的方法,更为重要的是,还发现了这种生长方法的内在机制,即质子辅助,这种方法有望推广到柔性电子学、高频晶体管等更多重要的研究领域。化学气相沉积方法(CVD)生长石墨烯,是目前制备大面积、高品质单晶晶粒或者薄膜的最主要方法。然而,由于石墨烯与基质材料能够产生强耦合作用,使得石墨烯在生长过程中会形成褶皱。褶皱的存在,会影响石墨烯的优良特性。     

RLVIP制备Ge1－xCx薄膜的X射线光电子能谱研究

应用低压反应离子镀（Reactive Low Voltage Ion Plating：RLVIP）在Ge基底上沉积了Ge1-xCx薄膜。制备过程中,低压等离子源作为辅助等离子源,Ge作为蒸发材料,CH4作为反应气体,在相同的条件下以不同沉积速率制备了C含量( x )从0.23到0.78的Ge1-xCx薄膜。X射线衍射测试表明制备的Ge1-xCx薄膜为无定形结构。通过X射线光电子能谱研究了不同C含量下Ge1-xCx薄膜的化学键合变化。测试结果表明当 x > 0.78时,成键为C-H键;当x在0.53至0.62时,成键为C-C键;当x < 0.47时,成键为Ge-C键。     

掠出射微区X射线荧光分析系统的建立及其在薄膜分析中的应用

介绍了一种综合导管X光透镜及全反射X射线荧光分析技术的掠出射微区X射线荧光分析方法,并将其应用北京师范大学低能核物理研究所离子束物理与技术教研室采用MEVVA源离子束和薄膜沉积技术制备的纳米金属单层纳米薄膜及纳米多层膜的分析。实验中所用X光透镜的焦斑大小为41.7μm。通过对薄膜样品的掠出射角度扫描分析,可得到薄膜特征X射线的掠出射角分布曲线,通过将实验曲线与理论模拟曲线进行拟合,可得到薄膜样品在微小区域的厚度及密度。结果表明,相比于通过薄膜沉积过程中的离子电量估计的薄膜厚度值,该方法测出的薄膜厚度更接近于薄膜的实际厚度。同时结果表明,使用MEVVA离子束薄膜沉积技术所镀薄膜的密度均小于体材料样品的密度值,且薄膜厚度的增加,薄膜密度逐渐增大并接近于体材料的密度值。另外,通过对薄膜样品表面进行二维扫描分析,实验中,扫描步长为50μm,扫描区域为500μm*500μm,可分析薄膜表面微小区域的均匀性。     

反应烧结碳化硅表面改性的初步研究

应用电子束蒸发硅,霍尔离子源电离甲烷,并辅助沉积的方法在反应烧结碳化硅(RB SiC)基底上沉积了碳化硅(SiC:H)改性薄膜.X射线衍射(XRD)测试表明制备的碳化硅改性薄膜为α相.通过控制沉积速率,制备了硬度为9.781～13.087GPa,弹性模量为89.344～123.413GPa的碳化硅改件薄膜.比较同样条件下镀制银膜的抛光良好微晶玻璃和经过精细抛光的改性 RB SiC,结果表明两者反射率相近;附着力实验表明,制备的薄膜和基底结合良好;在温度冲击实验下,制备的薄膜无龟裂和脱落.     

高性能新型金刚石薄膜刀具

金刚石薄膜刀具是90年代前后研制成功的一种新型刀具,其特点是:切削速度高,切削深度和进给量大,生产率高;切削力小,温升低,加工精度高可用于高速微切削精加工中;耐磨性好,耐用度是普通硬质合金刀具的50～100倍。目前它应用在有色合金、复合材料和许多非金属材料的切削加工中,正与多晶金刚石(polycrystalline diamond——PCD)、硬质合金和陶瓷刀具争夺市场。日美两国已开发成功各类金刚石薄膜车刀(指铣刀、钻头等刀具)。美国在短期内对这类刀具的销售额就达到7500万美元。金刚石薄膜是通过化学气相沉积(CVD)方法,使金刚石晶体沉积在碳化钨或陶瓷基底上,其厚度一般不大于50μm。目前的CVD方法以微波辅助CVD系统应用最多。该系统的金刚石薄膜沉积原理是:将氢气     

化学汽相沉积法制SnO2掺杂薄膜及其气敏特性的机理研究

】文中探讨用汽相沉积法制备ＳｎＯ２掺杂薄膜的不同工艺。研究ＳｎＯ２掺杂薄膜的光谱透过率气敏特性,测试掺５％Ａｇ的ＳｎＯ２薄膜在不同比例乙醇气体气敏作用下表面电阻气敏特性曲线。结果表明,汽相沉积法制备ＳｎＯ２掺杂薄膜工艺重复性好,灵敏度高,可用于制造新型的“气敏—光透过性”型气敏传感器。     

Characteristics of low-energy ion beams extracted from a wire electrode geometry

Beams of argon ions with energies less than 50 eV were extracted from an ion source through a wire electrode extractor geometry. A retarding potential energy analyzer (RPEA) was constructed in order to characterize the extracted ion beams. The single aperture RPEA was used to determine the ion energy distribution function, the mean ion energy and the ion beam energy spread. The multi-cusp hot cathode ion source was capable of producing a low electron temperature gas discharge to form quiescent plasmas from which ion beam energy as low as 5 eV was realized. At 50 V extraction potential and 0.1 A discharge current, the ion beam current density was around 0.37 mA/cm(2) with an energy spread of 3.6 V or 6.5% of the mean ion energy. The maximum ion beam current density extracted from the source was 0.57 mA/cm(2) for a 50 eV ion beam and 1.78 mA/cm(2) for a 100 eV ion beam.     

An ultra-low energy (30-200 eV) ion-atomic beam source for ion-beam-assisted deposition in ultrahigh vacuum

The paper describes the design and construction of an ion-atomic beam source with an optimized generation of ions for ion-beam-assisted deposition under ultrahigh vacuum (UHV) conditions. The source combines an effusion cell and an electron impact ion source and produces ion beams with ultra-low energies in the range from 30 eV to 200 eV. Decreasing ion beam energy to hyperthermal values (≈10(1) eV) without loosing optimum ionization conditions has been mainly achieved by the incorporation of an ionization chamber with a grid transparent enough for electron and ion beams. In this way the energy and current density of nitrogen ion beams in the order of 10(1) eV and 10(1) nA/cm(2), respectively, have been achieved. The source is capable of growing ultrathin layers or nanostructures at ultra-low energies with a growth rate of several MLs/h. The ion-atomic beam source will be preferentially applied for the synthesis of GaN under UHV conditions.     

Characterization of plasma parameters, first beam results, and status of electron cyclotron resonance source

Electron cyclotron resonance (ECR) plasma source at 50 keV, 30 mA proton current has been designed, fabricated, and assembled. Its plasma study has been done. Plasma chamber was excited with 350 W of microwave power at 2450 MHz, along with nitrogen and hydrogen gases. Microwave power was fed to the plasma chamber through waveguide. Plasma density and electron temperature were studied under various operating conditions, such as magnetic field, gas pressure, and transversal distance. Langmuir probe was used for plasma characterization using current-voltage variation. The nitrogen plasma density calculated was approximately 4.5 x 10(11) cm(-3), and electron temperatures of 3-10 eV (cold) and 45-85 eV (hot) were obtained. The total ion beam current of 2.5 mA was extracted, with two-electrode extraction geometry, at 15 keV beam energy. The optimization of the source is under progress to extract 30 mA proton beam current at 50 keV beam energy, using three-electrode extraction geometry. This source will be used as an injector to continuous wave radio frequency quadrupole, a part of 100 MeV proton linac. The required root-mean-square normalized beam emittance is less than 0.2pi mm mrad. This article presents the study of plasma parameters, first beam results, and status of ECR proton source.     

H- beam transport experiments in a solenoid low energy beam transport

The Front End Test Stand (FETS) is located at Rutherford Appleton Laboratory and aims for a high current, fast chopped 3 MeV H(-) ion beam suitable for future high power proton accelerators like ISIS upgrade. The main components of the front end are the Penning ion source, a low energy beam transport line, an radio-frequency quadrupole (RFQ) and a medium energy beam transport (MEBT) providing also a chopper section and rebuncher. FETS is in the stage of commissioning its low energy beam transport (LEBT) line consisting of three solenoids. The LEBT has to transport an H(-) high current beam (up to 60 mA) at 65 keV. This is the injection energy of the beam into the RFQ. The main diagnostics are slit-slit emittance scanners for each transversal plane. For optimizing the matching to the RFQ, experiments have been performed with a variety of solenoid settings to better understand the actual beam transport. Occasionally, source parameters such as extractor slit width and beam energy were varied as well. The paper also discusses simulations based on these measurements.     

Design and operating characteristics of new type cold cathode ion source

In this work, the design and performance of new type ion source are described. The discharge mechanism of the source is based on creating an arc discharge through a saddle electric field inside the discharge tube. The saddle electric field is created by immersing an annular anode inside the discharge tube covered from the upper and lower ends with two flanges. These two flanges act as cathodes. The discharge tube is surrounded by a solenoid coil which produces an axial magnetic field (up to 400 G) measured at the center of the source. Measurements have been performed to find out the influence of arc power, pressure, discharge voltage, magnetic field, and extracting voltage on the ion source properties. The source yields an argon ion current of approximately 0.6 mA and electron current of approximately 4 mA at normal operating conditions (extraction voltage V(ex)=7 kV, pressure of 5.5x10(-4) Torr, V(arc)=400 V, I(arc)=1 A, B=200 G). It showed an energy spread of 20 eV at a discharge voltage of 400 V and an extraction voltage of 3 kV.     

Optimizing the front end test stand high performance H- ion source at RAL

The aim of the front end test stand project is to demonstrate that chopped low energy H(-) beams of high quality can be produced. The beam line currently consists of the ion source, a 3 solenoid low energy beam transport and a suite of diagnostics. A brief status report of the radio frequency quadrupole is given. This paper details the work to optimize the ion source performance. A new high power pulsed discharge power supply with greater reliability has been developed to allow long term, stable operation at 50 Hz with a 60 A, 2.2 ms discharge pulse and up to 100 A at 1.2 ms. The existing extraction power supply has been modified to operate up to 22 kV. Results from optical spectroscopy measurements and their application to source optimization are summarized. Source emittances and beam currents of 60 mA are reported.     

A very low energy compact electron beam ion trap for spectroscopic research in Shanghai

In this paper, a new compact low energy electron beam ion trap, SH-PermEBIT, is reported. This electron beam ion trap (EBIT) can operate in the electron energy range of 60-5000 eV, with a current density of up to 100 A/cm(2). The low energy limit of this machine sets the record among the reported works so far. The magnetic field in the central drift tube region of this EBIT is around 0.5 T, produced by permanent magnets and soft iron. The design of this EBIT allows adjustment of the electron gun's axial position in the fringe field of the central magnetic field. This turned out to be very important for optimizing the magnetic field in the region of the electron gun and particularly important for low electron beam energy operation, since the magnetic field strength is not tunable with permanent magnets. In this work, transmission of the electron beam as well as the upper limit of the electron beam width under several conditions are measured. Spectral results from test operation of this EBIT at the electron energies of 60, 315, 2800, and 4100 eV are also reported.     

Electrical shielding box measurement of the negative hydrogen beam from Penning ion gauge ion source

The cold-cathode Penning ion gauge (PIG) type ion source has been used for generation of negative hydrogen (H(-)) ions as the internal ion source of a compact cyclotron. A novel method called electrical shielding box dc beam measurement is described in this paper, and the beam intensity was measured under dc extraction inside an electrical shielding box. The results of the trajectory simulation and dc H(-) beam extraction measurement were presented. The effect of gas flow rate, magnetic field strength, arc current, and extraction voltage were also discussed. In conclusion, the dc H(-) beam current of about 4 mA from the PIG ion source with the puller voltage of 40 kV and arc current of 1.31 A was extrapolated from the measurement at low extraction dc voltages.     

Development of a plasma generator for a long pulse ion source for neutral beam injectors

A plasma generator for a long pulse H(+)/D(+) ion source has been developed. The plasma generator was designed to produce 65 A H(+)/D(+) beams at an energy of 120 keV from an ion extraction area of 12 cm in width and 45 cm in length. Configuration of the plasma generator is a multi-cusp bucket type with SmCo permanent magnets. Dimension of a plasma chamber is 25 cm in width, 59 cm in length, and 32.5 cm in depth. The plasma generator was designed and fabricated at Japan Atomic Energy Agency. Source plasma generation and beam extraction tests for hydrogen coupling with an accelerator of the KSTAR ion source have been performed at the KSTAR neutral beam test stand under the agreement of Japan-Korea collaborative experiment. Spatial uniformity of the source plasma at the extraction region was measured using Langmuir probes and ±7% of the deviation from an averaged ion saturation current density was obtained. A long pulse test of the plasma generation up to 200 s with an arc discharge power of 70 kW has been successfully demonstrated. The arc discharge power satisfies the requirement of the beam production for the KSTAR NBI. A 70 keV, 41 A, 5 s hydrogen ion beam has been extracted with a high arc efficiency of 0.9 -1.1 A/kW at a beam extraction experiment. A deuteron yield of 77% was measured even at a low beam current density of 73 mA/cm(2).     

Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source

A plasma sputter-type negative ion source is utilized to produce and detect negative Zr ions with energies between 150 and 450 eV via a retarding potential-type electrostatic energy analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr ions and measure corresponding ion currents. The traditional FC registered indistinct ion current readings which are attributed to backscattering of ions and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into the data. The mean energy and energy spread are calculated using the ion current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of ion current. The most energetic negative Zr ions yield tighter energy spread at 4.11 eV compared to the least energetic negative Zr ions at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr ions with the highest mean energy indicating a more focused beam in contrast to the less energetic negative Zr ions due to space charge forces.