双能级离子束合成氮化类金刚石试验研究

以250-250eV的低能离子束轰击溅射石墨靶在钢上沉积非晶态碳膜,再以25-35keV的高能离子束将离化的双原子分子氮注入非晶态碳膜。纳米硬度分析表明了离子注氮后的硬度从20-30GPa提高到27-42Mpa范围;激光拉曼谱显示,膜的结构仍为非晶态,但所有拉曼参数发生变化,说明氮和碳形成化学键;X光电子能谱进一步揭示了氮注入碳后,氮峰位化学位移变化,隐示新相形成的可能性。结论：氮离子注入可形成氮化的类金刚石;双能级离子束轰击技术可提高氮在薄膜中的成分含量和碳膜的性能。     

改变过渡层碳靶功率在铜上沉积类金刚石膜的研究

类金刚石膜具有硬度高、 摩擦系数低、 耐腐性强、 稳定性高等优点, 是提高铜耐腐性的理想材料, 但铜 与类金刚石膜之间的结合力差。通过制备T i xC y 过渡层, 采用磁控溅射物理气相沉积与化学气相沉积法, 通过改变 过渡层碳靶功率成功在铜基体上沉积类金刚石膜。并对金刚石膜进行拉曼光谱测试、 划痕实验和电化学实验分析。 结果表明, 所制备碳膜具有典型的类金刚石结构, 膜与基体之间的结合强度大, 过渡层碳靶溅射功率为2 0 0W 时所 制备的类金刚石膜对铜基体的保护作用最好。     

离子注入金刚石拉丝模的电子顺磁共振特性分析

采用 EPR 技术对氮离子注入天然金刚石拉丝模进行了测试和分析。结果表明:氮离子注入后金刚石表面产生辐射缺陷。当离子能量为100kev,剂量达到5×10~(15)～10~(16)离子数/厘米~2时,金刚石表面出现连续非晶簿层。非晶态破坏了晶体表面的有序排列,有效地阻止了金刚石微裂变从而提高了拉丝耐磨性。当温度超过400℃以后,由于非晶层的再结晶过程。导致非晶化程度严重下降,降低了离子注入改性的效果。本文通过对金刚石表面非晶态的研究,解释了离子注入金刚石拉丝模延寿命;提出了选择最佳注入工艺条件的原则,并对其热稳定性作了分析。     

AZ31B镁合金表面沉积类金刚石膜的研究

类金刚石膜具有硬度高、摩擦系数低、耐腐性强、稳定性高等优良性质,是提高镁合金耐腐性的理想材料。但镁合金与类金刚石膜之间结合力差,本研究通过制备Si/SixNy过渡层成功解决了镁合金与类金刚石膜之间结合力差的问题。将磁控溅射物理气相沉积与化学气相沉积技术相结合,通过改变膜沉积偏压在镁合金表面沉积类金刚石膜。拉曼光谱测试表明,所制备的碳膜具有典型的类金刚石结构。划痕法测试表明,膜与基体之间的结合力非常大。最后通过失重实验分析了类金刚石膜对镁合金耐腐蚀性的影响。     

类金刚石膜的制备方法和性能

分析了类金刚石(DLC)膜的结构、性能及影响因素,对类金刚石膜的应用进行了阐述,并对DLC的几种制备方法,包括物理气相沉积法、化学气相沉积(CVD)和等离子体增强化学气相沉积法进行了介绍.     

H2对类金刚石薄膜性能影响的研究

类金刚石膜因其高的硬度、高的介电性、低的摩擦系数、优异的光学和化学性能以及巨大的潜在应用前景而成为研究热点。采用离子增加化学气相沉积方法在Si基底表面制备含氢类金刚石薄膜,通过XPS能谱测试,确定膜层的成份组成,膜层中除了含有碳以外还含少量的吸附的氧。调节反应源气体中H：的比例,结果表明H2的含量直接影响DLC薄膜的性能。随着H。的含量增大,膜层的表面粗糙度降低,膜层的硬度变大,而应力相应增大。这是由于反应源气体中H2含量的增加,DLC薄膜中氢的含量反而降低,膜层内sp2团簇结构的无序性增加,sp2键的比例增加,这将使得膜层内的碳的空间网络结构所占的比例增加。     

掺氮对纳米金刚石薄膜形貌及组成结构的影响

采用微波等离子体化学气相沉积技术,通过在甲烷和氢气的混合反应气源中通入不同浓度的氮气,合成了氮掺杂的纳米金刚石薄膜.表征结果表明随着氮气浓度的增加,所得到的金刚石薄膜的材料特征发生了明显的改变:膜层晶粒结构由从未见过的大尺寸片状向团簇状再向微颗粒状转变,并且薄膜的表面粗糙度相应变小;同时薄膜中非金刚石组份逐渐增多,膜材的物相纯度下降.氮气浓度除决定了纳米金刚石薄膜中N的掺杂度外,还会对膜材的物相组成、形貌及结构产生巨大的影响.     

金属-类金刚石薄膜研究进展

类金刚石膜中的金属粒子可缓解类金刚石薄膜中由于制备态产生大内应力而导致的膜厚受限这一矛盾,能显著改变薄膜各种性能.述评了金属-类金刚石薄膜的制备工艺、不同金属粒子对DLC薄膜形态、键结构、力学及摩擦磨损性能、物理化学性能等的影响,指出在金属粒子对DLC膜的力学及摩擦学性能的影响方面还有很多待确定的因素.     

低氮掺杂对含氢类金刚石结构和力学性能的影响

为探讨低氮掺杂对含氢类金刚石组织结构和力学性能的影响.采用非平衡磁控溅射和等离子增强化学气相沉积(PECVD)复合技术,在316不锈钢和硅片上制备碳化钨过渡层和不同掺氮量的含氢类金刚石薄膜(a-C:H(N)).通过拉曼光谱、X射线衍射(XRD)、X射线光电子能谱(XPS)和扫描电镜(SEM)对薄膜组织结构进行表征,薄膜的硬度和残余应力采用微纳米力学综合测量系统和薄膜应力测量仪进行表征.结果表明随着氮掺杂,薄膜形成碳氮键(CN)且其主要以C=N键形式存在,C=N/CN的比值随着薄膜氮含量增加逐渐下降.同时当掺氮量从0增至0.12 at%时,薄膜I_D/I_G比值迅速下降,sp~2C=C/sp~3C-C比值由0.65降至0.563,而薄膜硬度基本不变,约为20.4 GPa,残余应力则由3.35 Gpa降至1.31 GPa;随着掺氮量进一步增加,sp~2C=C/sp~3C-C比值增加,薄膜硬度迅速下降,残余应力则缓慢降低.可知氮的掺杂对DLC薄膜结构的影响有临界值0.12 at%,当掺氮量低于该值时,氮掺杂促进sp~3杂化的形成,薄膜具有较高的sp~3杂化含量.而随着薄膜含氮量进一步增加,sp~3杂化含量下降.同时当低氮掺杂时,可获得具有较高硬度以及较低残余应力的薄膜.     

类金刚石碳膜热稳定性的研究

研究了退火对类金刚石碳膜结构和性能的影响.结果表明:低于400℃退火对膜的结构、电阻率、硬度无明显影响;高于400℃退火,由于膜中氢原子的逸出,非晶碳将转变为石墨微晶,从而导致电阻率急剧下降;在400～700℃温度范围退火后,膜的硬度仍无明显变化.     

Electron Spectroscopy Studies on SiC Films before and after Hydrogen Ion Irradiation

1Introduction Theinteractionbetweenenergetichydrogenandlow Zmaterials,suchasSiC,hasbeenstudiedinseveral groupsbecausecarbidesoflowZelementsareusedfor plasmafacingcomponentsasfirstwallmaterialsin Tokamak[1,2].Hence,itisofinteresttounderstandthe effectsofHp…     

Hemocompatibility of DLC coatings synthesized by ion beam assisted deposition

Ion beam-assisted diamond-like carbon (DLC) coatings have been used for growing the human platelet, fibrinogen, and albumin in the control environment in order to assess their hemocom-patibility. The hard carbon films were prepared on polymethylmethacrylate (PMMA) at room temperature using ion beam assisted deposition (IBAD). Raman spectroscopic analysis proved that the carbon films on PMMA are diamond-like with a higher fraction of sp3 bonds in the structure of mixed sp2 + sp3 bonding. The blood protein adsorption tests showed that DLC coatings can adsorb more albumin and are slightly more fibrinogen than the PMMA chosen as a control sample. The platelets adhered on DLC coatings were reduced significantly in number. These results indicate good hemocompatibility of DLC coatings.     

Chemieal Bonding States of TiC Films before and after Hydrogen Ion Irradiation

TiC films deposited by rf magnetron sputtering followed by Ar＋ ion bombardment were irradiated with a hydrogen ion beam. X-ray photoelectron spectroscopy （XPS） was used for characterization of the chemical bonding states of C and Ti elements of the TiC films before and after hydrogen ion irradiation, in order to understand the effect of hydrogen ion irradiation on the films and to study the mechanism of hydrogen resistance of TiC films. Conclusions can be drawn that ion bombardment at moderate energy can cause preferential physical sputtering of carbon atoms from the surface of low atomic number （Z） material. This means that ion beam bombardment leads to the formation of a non-stoichiometric composition of TiC on the surface. TiC films prepared by ion beam mixing have the more excellent characteristic of hydrogen resistance. One important cause, in addition tO TiC itself, is that there are many vacant sites in TiC created by ion beam mixing. These defects can easily trap hydrogen and effectively enhance the effect of hydrogen resistance.     

Structure and Composition of Crystalline Carbon Nitride Films Synthesized by Microwave Plasma Chemical Vapor Deposition

Crystalline carbon nitride thin films were prepared on Si (100) substrates by a microwave plasma chemical vapor deposition method, using CH4/N2 as precursor gases. The surface morphologies of the carbon nitride films deposited on Si substrate at 830℃ are consisted of hexagonal crystalline rods. The effect of substrate temperature on the formation of carbon nitrides was investigated. X-ray photoelectron spectroscopy analysis indicated that the maximum value of N/C in atomic ratio in the films deposited at a substrate temperature of 830℃ is 1 .20, which is close to the stoichiometric value of C3N4. The X-ray diffraction pattern of the films deposited at 830℃ indicates no amorphous phase in the films, which are composed of β- and α-C3N4 phase containing an unidentified C-N phase. Fourier transform infrared spectroscopy supports the existence of C-N covalent bond.     

离子轰击辅助电子束蒸发制备含有纳米石墨结构的非晶碳膜

采用离子轰击辅助电子束蒸发技术制备了含有纳米石墨结构的碳膜。利用XRD、Ralnan和AFM等方法分析了碳膜的厚度、结构、相成分和形貌。结果表明制备的碳膜是一种具有纳米石墨结构的非晶碳膜。随着离子轰击能量的增大,碳膜的厚度随之减小,纳米石墨结构sp2团簇的尺寸变大,碳膜表面粗糙度增大,并找到了最佳的离子轰击能量。通过对Raman光谱分析发现,在最佳离子轰击能量下形成的纳米石墨结构sp2团簇尺寸大小约为2nm。     

Nano-sized Thin Films Fabricated by Ion Beam Sputtering and Its Properties

Nanoscale thick amorphous Ni-Cr alloy thin films were fabricated by low-energy ion beam sputtering technology; then the as-deposited samples experienced rapid thermal process to realize the transformation from amorphous to crystalline state. The film thickness was measured with a-stylus surface profiler, the structure and the compositions of the films were confirmed by low angle X-ray diffraction and scanning auger electron microprobe respectively, and the surface topography was characterized by scanning electron microscope and scanning probe microscope. Electrical property of the films was measured by fourpoint probe. The experimental results illustrate that the combined processes of ion beam sputtering and rajid thermal process are effective for fabrication nanoscale Ni-Cr alloy thin film with good properties.     

Preparation of silicon carbide nitride films on Si substrate by pulsed high-energy density plasma

Thin films of silicon carbide nitride （SiCN） were prepared on （111） oriented silicon substrates by pulsed high-energy density plasma （PHEDP）. The evolution of the chemical bonding states between silicon, nitrogen and carbon was investigated as a function of discharge voltage using X-ray photoelectron spectroscopy. With an increase in discharge voltage both the C 1s and N 1s spectra shift to lower binding energy due to the formation of C--Si and N--Si bonds. The Si--C--N bonds were observed in the deconvolved C ls and N ls spectra. The X-ray diffractometer （XRD） results show that there were no crystals in the films. The thickness of the films was approximately 1-2 μm with scanning electron microscopy （SEM）.     

Synthesis and characterization of well-aligned carbon nitrogen nanotubes by microwave plasma chemical vapor deposition

Well-aligned carbon nitrogen nanotube films have been synthesized successfully on meso-porous silica substrates by microwave plasma chemical vapor deposition (MWPCVD) method. Studies on their morphology, structure, and composition by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX), respectively, indicate that these nanotubes consist of linearly polymerized carbon nitrogen nanobells, and the nitrogen atoms have been doped into carbon netweork to form a new structure C1-xNx( x = 0.16±0.01). X-ray photoelectron spectroscopy (XPS) results of the samples further demonstrate that carbon bonds cova-lently with nitrogen in all the carbon nitrogen nanotube films.     

Structural and mechanical properties of amorphous carbon films deposited by the dual plasma technique

Direct current metal filtered cathodic vacuum are (FCVA) and acetylene gas (C2H2) were wielded to synthesize Ti-containing amorphous carbon films on Si (100). The influence of substrate bias voltage and acetylene gas on the microstructure and mechanical properties of the films were investigated. The results show that the phase of TiC in the (111) preferential crystallo-graphic orientation exists in the film, and rite main existing pattern of carbon is sp2. With increasing the acetylene flow rate, the con-tents of Ti and TiC phase of the film gradually reduce; however, the thickness of the film increases. When the substrate bias voltage reaches -600 V, the internal stress of the film reaches 1.6 GPa. The micro-hardness and elastic modulus of the film can reach 33.9 and 237.6 GPa, respectively, and the friction coefficient of the film is 0.25.     

等离子体化学气相沉积制备氮化碳薄膜

以H2、N2和CH4气体为前驱气体,通过等离子体化学气相沉积技术制备氮化碳薄膜。采用场发射扫描电子显微镜(FS-EM)及其附带的能量分散电子谱(EDS)、X射线衍射分析(XRD)、红外光谱(FTIR)和拉曼光谱(Raman)对其结构、表面形貌、元素含量和成键状况进行了分析,并讨论了气体流量比和放电功率对薄膜制备的影响。实验结果表明:沉积的薄膜中含有晶态的C3N4,碳氮原子比接近于理论值0.75,样品中碳氮原子多以C N、C N的形式存在;样品中氮元素的含量随着反应气体中N2含量的增加而增加;放电功率的增大使薄膜的沉积速率增大。