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1.
采用大直径中空柱状阴极直流磁控制溅射装置,在LaAlO3和Zr(Y)O2衬底上制备YBCO超导薄膜。用透射电镜(TEM)、扫描隧道显微镜(SIM)和原子力显微镜(AFM)对薄膜和衬底间的界面,薄膜的螺旋生长结构,YBCO薄膜及其相应衬底的表面形貌进行了观察和测量。分析了基片表面形貌及表层内缺陷对界面附近薄膜组织结构的影响。研究了不同衬底沉积的超导薄膜具有不同表面形貌的原因。从生长机理角度对表面形貌、缺陷和位错的形成机制进行讨论。 相似文献
2.
采用液相电化学沉积技术制备了ZnO纳米颗粒掺杂的类金刚石(DLC)薄膜, 研究了ZnO纳米颗粒掺杂对DLC薄膜场发射性能的影响. 利用X射线光电子能谱、透射电子显微镜、Raman光谱以及原子力显微镜分别对薄膜的化学组成、 微观结构和表面形貌进行了表征. 结果表明: 薄膜中的ZnO纳米颗粒具有纤锌矿结构, 其含量随着电解液中Zn源的增加而增加. ZnO纳米颗粒掺杂增强了DLC薄膜的石墨化和表面粗糙度. 场发射测试表明, ZnO纳米颗粒掺杂能提高DLC薄膜的场发射性能, 其中Zn与Zn+C的原子比为10.3%的样品在外加电场强度为20.7 V/μm时电流密度达到了1 mA/cm2. 薄膜场发射性能的提高归因于ZnO掺杂引起的表面粗糙度和DLC薄膜石墨化程度的增加. 相似文献
3.
强激光辐照红外热像系统时,可造成系统的干扰和破坏,激光的波长不同,对系统的破坏效果也不同.为了保护红外系统窗口以及提高窗口的透过率,红外窗口广泛沉淀类金刚石(DLC)薄膜.当入射的激光波长位于红外系统响应波段外时,激光对系统的破坏首先是激光对DLC薄膜的破坏.以波长为1.06μm的激光为例,研究了脉冲激光对DLC薄膜的损伤机理,建立了DLC薄膜的热冲击效应模型,并通过求解热传导和应力平衡方程,得出了薄膜的温度场和应力场分布.理论分析表明,热应力破坏在脉冲强激光对DLC膜的损伤机理中占主导地位.当 辐照能量密度为E0=100mJ·cm-2时,在薄膜表面距光斑中心约 40μm区域内的压应 力明显超出其断裂强度,将造成膜层的剥离、脱落.理论分析与实验结果基本相符,表明建 立热冲击效应模型的正确性.
关键词:
激光辐照
类金刚石(DLC)薄膜
热冲击效应 相似文献
4.
利用分子动力学模拟方法,从原子尺度上研究了类金刚石(DLC)薄膜生长过程. 按照运动特点把入射原子在表面的行为分为表面冷冻、迁移、注入和反弹等四种,并由此提出原子运动模型. 入射原子的表面行为对DLC薄膜的微观结构以及生长方式有重要影响. 其中原子水平迁移是薄膜热弛豫的主要途径,入射原子的注入和迁移行为相互竞争,决定了薄膜生长的模式和最终结构. 利用统计分析手段给出了入射能量对原子表面行为进而对薄膜结构的影响,加深了对DLC薄膜生长机理的认识. 相似文献
5.
��������ɣ��������������������������ΰ���� ǿ 《核聚变与等离子体物理》2018,38(3):368-372
报道了利用多腔耦合微波表面波等离子体增强化学气相沉积(PECVD)的方法制备类金刚石(DLC)薄膜。通过发射光谱(OES)测量,对Ar等离子体中的各种放电参数以及全部四个腔室内放电的均匀性作出评估。采用表面轮廓仪测量了薄膜的厚度;薄膜的表面形貌、组成结构通过原子力显微镜(AFM)、激光拉曼光谱和X射线衍射光谱(XPS)进行了表征。在12.5μm厚度的有机薄膜聚酯(PET)表面沉积一定厚度DLC后,通过测量水蒸气透过率(WVTR)对DLC薄膜的阻隔性能进行了研究。结果表明,这种多腔耦合微波表面波等离子体装置,不仅能够实现四个腔室同时相对均匀的放电,也能够实现单个腔室的轴向均匀放电。制备的DLC薄膜结构致密、成分均匀,可以使PET薄膜阻隔性能提高约20倍。 相似文献
6.
报道了利用多腔耦合微波表面波等离子体增强化学气相沉积(PECVD)的方法制备类金刚石(DLC)薄膜。通过发射光谱(OES)测量,对Ar等离子体中的各种放电参数以及全部四个腔室内放电的均匀性作出评估。采用表面轮廓仪测量了薄膜的厚度;薄膜的表面形貌、组成结构通过原子力显微镜(AFM)、激光拉曼光谱和X射线衍射光谱(XPS)进行了表征。在12.5μm厚度的有机薄膜聚酯(PET)表面沉积一定厚度DLC后,通过测量水蒸气透过率(WVTR)对DLC薄膜的阻隔性能进行了研究。结果表明,这种多腔耦合微波表面波等离子体装置,不仅能够实现四个腔室同时相对均匀的放电,也能够实现单个腔室的轴向均匀放电。制备的DLC薄膜结构致密、成分均匀,可以使PET薄膜阻隔性能提高约20倍。 相似文献
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8.
采用分子动力学(MD)模拟方法,从原子尺度上研究了离子束辅助沉积(IBAD)类金刚石(DLC)薄膜过程中离子束入射角对薄膜结构的影响.重点讨论了不同的离子束入射角所对应的薄膜表面模型,平均密度和sp3键含量.结果表明,离子束斜入射加强了入射原子的水平动能,从而加强了原子水平迁移;Ar离子斜入射时C原子迁移率均比垂直入射大,薄膜密度和sp3键含量都比垂直入射小.不同的离子束入射角随着到达比和入射能的变化,对薄膜结构的影响不同.离子束斜入射时可以得到不同结构的膜.
关键词:
类金刚石薄膜
入射角
离子束辅助沉积
分子动力学模拟 相似文献
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10.
为了使研究者能更详细地了解类金刚石(DLC)薄膜的研究现状,综述了类金刚石薄膜的特性及应用,分析对比了目前常用的一些类金刚石薄膜的制备方法,包括物理气相沉积法(PVD)和化学气相沉积法(CVD),并对类金刚石薄膜的抗强激光损伤特性以及提高其激光损伤阈值的方法进行了论述。结果发现,利用PVD法制备的DLC膜的硬度可以达到40 GPa~80 GPa,且薄膜的残余应力可以达到0.9 GPa~2.2 GPa之间,而CVD法则由于反应气体的充入导致类DLC薄膜的沉积速率大大降低,故使用率不高。同时,优化膜系的电场强度设计,采用合理的制备工艺,进行激光辐照后处理,施加外界电场干预均可有效地提高DLC薄膜的抗激光损伤能力, 且目前的DLC薄膜的激光损伤阈值可达到2.4 J/cm2。 相似文献
11.
《Applied Surface Science》2005,239(3-4):255-258
A well adherent diamond-like carbon (DLC) film was deposited on piezoelectric LiTaO3 substrate using PECVD by inserting SiO2 interlayer. DLC film was characterized using Raman spectroscopy and AFM. Physical and mechanical properties were measured using XRR, ellipsometry, scratch test and nano-indentation. The DLC film exhibits the characteristics of hydrogenated amorphous carbon and a very smooth surface with a 0.25 nm RMS. Scratch test shows that critical load (Lc) is 18 N, which is good enough for applying DLC film to SAW device. The measured mass density, refractive index, hardness and Young’s modulus of DLC film deposited on LiTaO3 are comparable to the reported values for hydrogenated amorphous carbon film, irrespective of substrates on which the films were deposited. 相似文献
12.
The effect of substrate roughness on growth of ultra thin diamond-like carbon (DLC) films has been studied. The ultra thin DLC films have been deposited on silicon substrates with initial surface roughness of 0.15, 0.46 and 1.08 nm using a filted cathodic vacuum arc (FCVA) system. The films were characterized by Raman spectroscope, transmission electron microscope (TEM) and atomic force microscopy (AFM) to investigate the evolution of the surface roughness as a function of the film thickness. The experimental results show that the evolution of the surface morphology in an atomic scale depends on the initial surface morphology of the silicon substrate. For smooth silicon substrate (initial surface roughness of 0.15 nm), the surface roughness decreased with DLC thickness. However, for silicon substrate with initial surface roughness of 0.46 and 1.08 nm, the film surface roughness decreased first and then increased to a maximum and subsequently decreased again. The preferred growth of the valley and the island growth of DLC were employed to interpret the influence of substrate morphology on the evolution of DLC film roughness. 相似文献
13.
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
14.
采用飞秒激光(800 nm,120 fs,3 W,1 000 Hz)制备类金刚石膜,研究了不同偏压、生长温度和氧气氛等辅助手段对激光沉积类金刚石膜的影响,实验发现在室温(25℃)、无偏压和低气压氧气氛(2 Pa)条件下沉积的类金刚石膜性能最优。在单面预镀普通增透膜的硅红外窗口材料上镀制出了无氢类金刚石膜,3~5μm波段平均透过率达到90%以上,纳米硬度高达40 GPa,用压力为9.8 N的橡皮磨头,摩擦105次,膜层未见磨损,并且通过了军标规定的高温、低温、湿热、盐雾等环境试验,所制类金刚石膜可对红外窗口起到较好的增透保护作用。 相似文献
15.
K. Siraj M. Khaleeq-ur-RahmanM.S. Rafique M.Z. MunawarS. Naseem S. Riaz 《Applied Surface Science》2011,257(15):6445-6450
Cobalt-DLC multilayer films were deposited with increasing content of cobalt, keeping carbon content constant by pulsed laser deposition technique. A cobalt free carbon film was also deposited for comparison. Excimer laser was employed to ablate the materials onto silicon substrate, kept at 250 °C, while post-deposition annealing at 400 °C was also performed in situ. The formation of cobalt grains within the carbon matrix in Co-DLC films can be seen through scanning electron and atomic force micrographs while no grains on the surface of the cobalt-free DLC film were observed. Raman spectra of all the films show D- and G-bands, which is a confirmation that the films are DLC in nature. According to Vibrating sample magnetometer (VSM) measurements, the DLC films with cobalt revealed ferromagnetic behaviour whereas the cobalt free DLC film exhibited diamagnetic behaviour. The pure DLC film also shows ferromagnetic nature when diamagnetic background is subtracted. Spectroscopic Ellipsometry (SE) analysis showed that the optical band gaps, refractive indices and extinction coefficients of Co-DLC films can be effectively tuned with increasing content of cobalt. 相似文献
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17.
A series of diamond-like carbon (DLC) films with different microstructure were prepared by depositing carbon atoms on diamond surface with incident energy ranging from 1 to 100 eV. The thermal conductivity of the deposited films and the Kapitza resistance between the film and the diamond substrate were investigated. Results show that the average density, the average fraction of sp3 bonding and the thermal conductivity of the DLC films increase first, reaching a maximum around 20–40 eV before decreasing, while the Kapitza resistance decreases gradually with increased deposition energy. The analysis suggests that the thermal resistance of the interface layer is in the order of 10?10 m2K/W, which is not ignorable when measuring the thermal conductivity of the deposited film especially when the thickness of the DLC film is not large enough. The fraction of sp3 bonding in the DLC film decreases gradually normal to the diamond surface. However, the thermal conductivity of the film in normal direction is not affected obviously by this kind of structural variation but depends linearly on the average fraction of sp3 bonding in the entire film. The dependence of the thermal conductivity on the fraction of sp3 bonding was analysed by the phonon theory. 相似文献
18.
Tribological properties of diamond-like carbon films deposited by pulsed laser arc deposition 总被引:1,自引:0,他引:1 下载免费PDF全文
A novel method, pulsed laser arc deposition combining the advantages
of pulsed laser deposition and cathode vacuum arc techniques, was
used to deposit the diamond-like carbon (DLC) nanofilms with
different thicknesses. Spectroscopic ellipsometer, Auger electron
spectroscopy, x-ray photoelectron spectroscopy, Raman spectroscopy,
atomic force microscopy, scanning electron microscopy and
multi-functional friction and wear tester were employed to
investigate the physical and tribological properties of the deposited
films. The results show that the deposited films are amorphous and
the sp$^{2}$, sp$^{3}$ and C--O bonds at the top surface of the films
are identified. The Raman peak intensity and surface roughness
increase with increasing film thickness. Friction coefficients are
about 0.1, 0.15, 0.18, when the film thicknesses are in the range of
17--21~nm, 30--57~nm, 67--123~nm, respectively. This is attributed to
the united effects of substrate and surface roughness. The wear
mechanism of DLC films is mainly abrasive wear when film thickness
is in the range of 17--41~nm, while it transforms to abrasive
and adhesive wear, when the film thickness lies between 72 and 123~nm. 相似文献
19.
In this work, investigations were conducted to analyze the properties of diamond-like carbon (DLC) film deposited on ultra-high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) at a low temperature of 50 °C. Composition and structure of the films were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. Hardness and wettability of the film were tested. Tribological characterizations were carried out on a universal micro-tribometer, and reciprocating friction against ZrO2 ball was adopted with 25% bovine serum as lubrication. Results show that DLC film was successfully deposited on UHMWPE surface by RF-PECVD and the sp3 content was about 20% in the film. The film increased the macrohardness of the substrate by about 42% and the wettability was improved too. Tribology test showed a higher friction coefficient but a much smaller wear volume after the deposition due to the surface roughening and strengthening. 相似文献