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1.
类金刚石薄膜红外光学常数的计算机拟合 总被引:2,自引:1,他引:1
报道了一种对类金刚石薄膜红外透射率曲线最小二乘法拟合的方法,确定类金刚石薄膜的红外光学常数-折射率、吸收系数以及薄膜厚度及表面粗糙度。介绍了相应的数学模型,并给出了对类金刚石薄膜样品的实验测及拟合结果。 相似文献
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采用热丝化学气相沉积法制备硼掺杂纳米金刚石 (BDND) 薄膜, 并对薄膜进行真空退火处理, 系统研究退火温度对BDND薄膜微结构和电学性能的影响. Hall效应测试结果表明掺B浓度为5000 ppm (NHB) 的样品的电阻率较掺B浓度为500 ppm (NLB) 的样品的低, 载流子浓度高, Hall迁移率下降. 1000 ℃退火后, NLB和NHB 样品的迁移率分别为53.3和39.3 cm2·V-1·s-1, 薄膜的迁移率较未退火样品提高, 电阻率降低. 高分辨透射电镜、紫外和可见光拉曼光谱测试结果表明, NLB样品的金刚石相含量较NHB样品高, 高的硼掺杂浓度使薄膜中的金刚石晶粒产生较大的晶格畸变. 经1000 ℃退火后, NLB和NHB薄膜中纳米金刚石相含量较未退火时增大, 说明薄膜中部分非晶碳转变为金刚石相, 为晶界上B扩散到纳米金刚石晶粒中提供了机会, 使得纳米金刚石晶粒中B浓度提高, 增强纳米金刚石晶粒的导电能力, 提高薄膜电学性能. 1000 ℃退火能够恢复纳米金刚石晶粒的晶格完整性, 减小由掺杂引起的内应力, 从而提高薄膜的电学性能. 可见光Raman光谱测试结果表明, 1000℃退火后, Raman谱图中反式聚乙炔 (TPA) 的1140 cm-1峰消失, 此时薄膜电学性能较好, 说明TPA减少有利于提高薄膜的电学性能. 退火后金刚石相含量的增大、金刚石晶粒的完整性提高及TPA含量的大量减少有利于提高薄膜的电学性能.
关键词:
硼掺杂纳米金刚石薄膜
退火
微结构
电学性能 相似文献
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《光子学报》2021,50(6)
为了探究皮秒激光加工金刚石的特征和材料去除机理,开展了皮秒激光加工CVD单晶金刚石微槽的试验和温度场仿真研究。利用场发射扫描电子显微镜检测了金刚石微槽表面和内部的微观形貌,实验结果表明,金刚石微槽边缘出现了微小崩边和微裂纹,微槽内部形成了周期约为255 nm和495 nm的纳米条纹。通过测量金刚石微槽宽度、深度、体积,得到了皮秒激光烧蚀金刚石的阈值、烧蚀速率和材料去除率。对金刚石微槽底部进行拉曼分析,发现皮秒激光加工金刚石是通过表面石墨化进行的,并且随着激光能量密度的增加,石墨峰出现了明显的红移。理论计算得到皮秒激光烧蚀金刚石的石墨层厚度约为88.7 nm。皮秒激光烧蚀金刚石温度场仿真结果表明,皮秒激光辐照能量主要分布在金刚石的表面,而通过热传导进入到金刚石内部的激光能量极少,因此皮秒激光加工金刚石的热影响区极小,导致其产生的石墨层厚度小于100 nm。 相似文献
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用YAG激光制备类金刚石薄膜及其光学折射率研究 总被引:2,自引:2,他引:0
用高功率的Nd^3+:YAG脉冲激光轰击真空室内的石墨靶,形成激光等离子体雾状物质,在硅衬底上沉积形成类金刚石薄膜,用椭圆偏振光谱法测量不同衬底温度下制备的系列样品的厚度和折射率,发现随着衬底温度的升高,薄膜的厚度减小而的折射率增大,这种可以控制折射率米化的薄膜,可能为光学增透增反膜的制备提供一种新方法。 相似文献
6.
高党忠 《工程物理研究院科技年报》2009,(1):9-10
惯性约束聚变(ICF)物理实验研究中,10-100μm厚度的Al,Cu等白支撑金属薄膜是常用的靶材料,由于薄膜厚度及其分布与冲击波速度、压强等物理实验结果直接相关,因此需要对其厚度进行精确的测量。长期以来,对薄膜样品厚度的测量主要采用传统的单面定位测量法,但由于薄膜一基底之间的定位误差,薄膜厚度的精密测量存在难以克服的技术难题。 相似文献
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分别以富集有Cr,Pb和Cd三种元素的尼龙薄膜样品及玻璃纤维滤膜为研究对象,采用滤膜叠加的方式,通过XRF光谱仪测量不同样品厚度下薄膜样品的XRF光谱,根据测得的尼龙薄膜样品中Cr,Pb,Cd元素及玻璃纤维滤膜中Ca,As和Sr元素特征XRF性质的变化,研究样品厚度对薄膜法XRF光谱测量的影响。结果表明:薄膜样品厚度对不同能量区间上元素特征谱线荧光性质的影响并不相同。元素特征谱线能量越大,元素特征X射线荧光穿透滤膜到达探测器的过程中损失越少;但由薄膜样品厚度增加引起的基体效应却越强,相应特征谱线位置处的背景荧光强度就越大,因此样品厚度增加所引起的基体效应对薄膜法XRF光谱测量的灵敏度影响就越大。对于特征谱线能量较低(能量小于7 keV)的元素,以增加薄膜样品厚度的方式来增加待测组分的质量厚度浓度,并不能有效地提高薄膜法XRF光谱测量的灵敏度;对于特征谱线能量较高的元素(能量>7 keV),可以通过适当增加样品厚度以增加被测组分的质量厚度浓度的方式来提高XRF光谱测量的灵敏度,薄膜样品厚度在0.96~2.24 mm内,更有利于XRF光谱的测量与分析。该研究为大气及水体重金属薄膜法XRF光谱分析中薄样制备及富集技术提供了重要的理论依据。 相似文献
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《光学学报》2010,(8)
采用乙烷气体辉光放电法在单晶Si衬底上制备了名义厚度分别为75,150和250nm的类金刚石碳(DLC)薄膜,除沉积时间外其他工艺参数完全一致。使用可变入射角光谱型椭偏仪(VASE)测量了380~1700nm波段的椭偏谱。该研究发现,对单一DLC样品的椭偏数据进行分析时,一定的范围内,假定不同的薄膜厚度均可以得到非常好的拟合结果。结果表明,采用单样品椭偏法拟合时,厚度与光学常数呈现出强烈的关联性,无法快速获得准确的结果。采用多样品椭偏法,对三个样品建立相同的物理模型,假定他们的光学常数相同,进行数据拟合。分析发现该方法可以快速、简便地获得精确的折射率、消光系数以及厚度值。经过检验,结果具有非常好的唯一性。 相似文献
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Xinchun ChenZhijian Peng Xiang YuZhiqiang Fu Wen YueChengbiao Wang 《Applied Surface Science》2011,257(8):3180-3186
In order to smooth the rough surface and further improve the wear-resistance of coarse chemical vapor deposition diamond films, diamond/tetrahedral amorphous carbon composite films were synthesized by a two-step preparation technique including hot-filament chemical vapor deposition for polycrystalline diamond (PCD) and subsequent filtered cathodic vacuum arc growth for tetrahedral amorphous carbon (ta-C). The microstructure and tribological performance of the composite films were investigated by means of various characterization techniques. The results indicated that the composite films consisted of a thick well-grained diamond base layer with a thickness up to 150 μm and a thin covering ta-C layer with a thickness of about 0.3 μm, and sp3-C fraction up to 73.93%. Deposition of a smooth ta-C film on coarse polycrystalline diamond films was proved to be an effective tool to lower the surface roughness of the polycrystalline diamond film. The wear-resistance of the diamond film was also enhanced by the self-lubricating effect of the covering ta-C film due to graphitic phase transformation. Under dry pin-on-disk wear test against Si3N4 ball, the friction coefficients of the composite films were much lower than that of the single PCD film. An extremely low friction coefficient (∼0.05) was achieved for the PCD/ta-C composite film. Moreover, the addition of Ti interlayer between the ta-C and the PCD layers can further reduce the surface roughness of the composite film. The main wear mechanism of the composite films was abrasive wear. 相似文献
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The incorporation of hydrogen within ultrananocrystalline diamond/amorphous carbon composite films has been investigated by nuclear reaction analysis (NRA) and Fourier transform infrared spectroscopy (FTIR). The film bulk contains ca. 7.5–8% H (for a deposition temperature of 600 °C), while the H concentration in the surface region is considerably higher. FTIR measurements show that the hydrogen‐rich surface is formed right at the beginning of the deposition process and grows outward as the film thickness increases. It can thus be concluded that surface hydrogen species play an active role in the formation of ultrananocrystalline diamond/amorphous carbon films. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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An analytical method for simulating gas phase film growth has been developed and used to study the growth of diamond films
during prolonged deposition, i.e. the film thickness is much larger than the lateral grain size. From a model system composed
of 104 grains, reliable results can be evaluated for the growth of diamond films by (111) and (001) deposition under different initial
conditions and with varying growth parameters. It is demonstrated that the rate of structure evolution is sensitively influenced
by the aspect ratio of diamond crystal. A near-linear proportionality between the average grain size and the thickness of
films can be approximately yielded for a large film thickness which is about 10 times of the average distance of the nuclei.
The proportionality constant varies for a statistical nucleation from 0.0056 to 0.43 by changing the aspect ratio. Furthermore,
the orientational distribution is drastically narrowed down so that the probability of coalescence of grains with a slight
orientational difference is considerably increased.
Received: 28 September 2000 / Accepted: 19 February 2001 / Published online: 3 May 2001 相似文献
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采用微波等离子体化学气相沉积(MW-PCVD)和直流热阴极辉光放电等离子体化学气相沉积(DC-PCVD)两种方法相结合,制备出一种吸收辐射的复合金刚石膜,它对宽光谱范围的光辐射具有99%—99.2%的吸收率,同时具有较低的反射率和透过率.随着黑色吸收辐射金刚石层厚度的增加,复合金刚石膜的热导率将小幅度降低,但黑色金刚石膜层厚度小于15 μm时,复合金刚石膜的热导率都在16 W·cm-1·K-1以上,这满足吸收辐射复合金刚石膜的高导热需求.用热阴极DC-PCVD方
关键词:
吸收辐射
光学材料
金刚石
热导率 相似文献
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Finite element analysis of three-dimensional laser-induced transient thermal grating in diamond/ZnSe system 下载免费PDF全文
This paper uses finite element method to obtain the three-dimensional temperature field of laser-induced transient thermal grating (TTG) for two-layered structure of diamond film on ZnSe substrate. The numerical results indicate that unique two-times heating process is gradually experienced in the area between two adjacent grating stripes. However, there is a little change for the temperature field along the depth direction for the diamond film due to its great thermal conductivity. It further finds that the thickness of the diamond film has a significant influence on the temperature field in diamond/ZnSe system. The results are useful for the application of laser-induced TTG technique in film/substrate system. 相似文献
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With the increase of magnetic storage density, the thickness of the protective diamond like carbon (DLC) film on the surfaces of head and disk is required as thin as possible. In this paper, the structure, mechanical properties and corrosion and oxidation resistance of ultra-thin DLC films are investigated. The ultra-thin DLC films were deposited by using filtered cathodic vacuum arc (FCVA) technique. The exact thickness of the ultra-thin DLC film was determined by high resolution transmission electron microscope (HRTEM). Raman analysis indicates that the ultra-thin DLC film presents ta-C structure with high sp3 fraction. In the wear test, a diamond tip was used to simulate a single-asperity contact with the film surface and the wear marks were produced on the film surface. The wear depths decrease with film thickness increasing. If the film thickness was 1.4 nm or above, the wear depth was much lower than that of Si substrate. This indicates that the ultra-thin DLC film with thickness of 1.4 nm shows excellent wear resistance. Corrosion tests in water and oxidation tests in air were carried out to investigate the diffusion barrier effect of the ultra-thin DLC films. The results show that the DLC film with thickness of 1.4 nm provides adequate coverage on the substrate and has good corrosion and oxidation resistance. 相似文献
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QIU Hong FAN Zhengxiu 《Chinese Journal of Lasers》1998,7(1):73-78
LaserInducedDamageinCVDDiamondFilmsQIUHongFANZhengxiu(ShanghaiInstituteofOpticsandFineMechanics,ChineseAcademyofSciences,P.O.... 相似文献
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A tungsten-carbide gradient coating (WCGC) was prepared by reactive sputtering as an intermediate layer on the cemented carbide, WC-13 wt.% Co, substrate to improve the nucleation, smoothness and adhesion of diamond film. The diamond film was deposited by hot filament chemical vapor deposition (HFCVD). The effects of the substrate temperature on the WCGC and the diamond film were investigated. The characterization of the WCGC and the diamond films was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), micro-Raman spectroscopy and Rockwell hardness indentation. It is found that the WCGC plays an important role in improving the nucleation, smoothness and adhesion of diamond film; and the diamond films exhibit better quality and adhesion as substrate temperature increases during the CVD processes. 相似文献
20.
Effect of electromechanical boundary conditions on the properties of epitaxial ferroelectric thin films 下载免费PDF全文
The effects of internal stresses and depolarization fields on the properties of epitaxial ferroelectric perovskite thin films are discussed by employing the dynamic Ginzburg-Landau equation (DGLE). The numerical solution for BaTiO3 film shows that internal stress and the depolarization field have the most effects on ferroelectric properties such as polarization, Curie temperature and susceptibility. With the increase of the thickness of the film, the polarization of epitaxial ferroelectric thin film is enhanced rapidly under high internal compressively stress. With the thickness exceeding the critical thickness for dislocation formation, the polarization increases slowly and even weakens due to relaxed internal stresses and a weak electrical boundary condition. This indicates that the effects of mechanical and electrical boundary conditions both diminish for ferroelectric thick films. Consequently, our thermodynamic method is a full scale model that can predict the properties of ferroelectric perovskite films in a wide range of film thickness. 相似文献