纳米结构洋葱状富勒烯的CCVD法制备

纳米结构洋葱状富勒烯(NSOFs)是准球体同心壳层形状的碳笼构成的富勒烯分子，由于其独特的结构及性能，具有极富潜力的应用前景。现有的制备洋葱状富勒烯的方法有高能电子束辐照含碳物质、水中电弧放电法、纳米金刚石粉热处理和射频等离子CVD等。但由于上述种种方法的制备条件苛刻，不适合工     

真空热处理条件下纳米洋葱状富勒烯的结构

纳米洋葱状富勒烯（NanoOnion-like Fullerenes,NOLFs）作为富勒烯家族的一个新成员自1992年被发现以来由于其独特的中空笼状结构和潜在的应用前景引起研究者广泛的关注。目前，制备NOLFs的主要方法有电弧放电法、等离子体法，化学气相沉积法和真空热处理法。本文以金属Ni为催化剂，石墨粉为碳源探讨了真空热处理条件下温度对NOLFs结构形态的影响。     

煤制备洋葱状富勒烯的HREM分析

采用直流电弧放电法以煤为原料制备富勒烯。实验采用工作气体为Ar，催化剂选用纳米Cu颗粒。所得到的阴极产物的HREM观察表明：在适当的工艺条件和催化剂作用下，可宏量制备出碳纳米颗粒—洋葱状富勒烯(nano-structured onion-like-fullerenes；NSOFs)，直径为25～40nm；同时生成一些特殊形状的碳纳米管，其形状为探讨高温条件下碳纳米管向洋葱状富勒烯转变提供了有力的证据；煤的独特结构使其在制备过程中沿两条路径形成富勒烯：非晶态碳原子的石墨化和芳香结构的重排。X射线能谱分析表明煤中舍有Mg、Si、S等微量矿物元素，这些元素的存在意味着可能对洋葱状富勒烯的生成有催化作用，     

金属微粒催化制备洋葱状富勒烯的研究

在富勒烯被发现后，科学家就预言富勒烯笼内可容纳一个或几个原子而形成富勒烯包合物。Heath等通过激光气化LaCl3浸泡过的石墨获得了金属富勒烯的质谱信息，掀起了富勒烯包合物的研究热潮。富勒烯内包金属有着新颖独特的结构，必将在超导、信息通讯、生物医学等方面有着诱人的发展前景。     

Pt／洋葱状富勒烯复合纳米微粒的制备

洋葱状富勒烯（OLFs）是继C60、碳纳米管之后人们发现的又一种崭新的全碳物质，自1992年Ugarte发现洋葱状富勒烯（onion-like fullerenes，OLFs）以来，其研究成为物理、化学和纳米材料科学等领域的热点。OLFs独特的中空笼状及同心壳层结构，可以容纳原子团簇、纳米微粒和金属碳化物等，具有许多特殊性能，有望在能源材料、高性能高温耐磨材料、超导材料和生物医用材料等领域被广泛应用。     

氧化物催化电弧法制备洋葱状富勒烯的研究

纳水洋葱状富勒烯作为富勒烯家族中的新成员，自1992年被发现以来，已在全世界范围内引起了各国学者的广泛关注和极大兴趣。然而，由于缺乏有效宏量制备纳米洋葱状富勒烯的方法，目前的研究仍处于实验室阶段。我们课题组在自制的直流电弧放电设备中，不断改进放电工艺，用多种催化剂(Ti、Fe、Ni、     

洋葱状富勒烯的水中放电制备法

自1992年洋葱状富勒烯（onion-like fullerenes,OLFs）被发现以来,由于其在超导、耐磨和非线性光学等领域显示了巨大的潜在应用价值,引起了科学界的广泛关注。然而到目前为止,制备OLFs通常所采用的传统电孤放电法、电子束辐照法、碳离子注入法等方法中还没有一种能够满足OLFs低成本宏量制备的要求。     

聚乙二醇放电介质中洋葱状富勒烯的制备与表面修饰

以分子量为600、400和200的聚乙二醇（PEG）为介质电弧放电法制备了洋葱状富勒烯（OLFs）;利用空气氧化法于450℃条件下对产物进行了提纯,并用含氧射频等离子体对纯化后的OLFs进行了表面氧化修饰;用场发射扫描电镜、高分辨透射电镜、X射线衍射和傅立叶变换红外光谱对所得产物进行了表征和分析。结果表明：在PEG200中放电制得的OLFs粒径均匀,石墨化程度较高;空气氧化法能提高OLFs产物的纯度;当氧气含量为20%时,表面氧化修饰效果明显。     

聚乙二醇放电介质中洋葱状富勒烯的制备与表面修饰

以分子量为600、400和200的聚乙二醇（PEG）为介质电弧放电法制备了洋葱状富勒烯（OLFs）;利用空气氧化法于450℃条件下对产物进行了提纯,并用含氧射频等离子体对纯化后的OLFs进行了表面氧化修饰;用场发射扫描电镜、高分辨透射电镜、X射线衍射和傅立叶变换红外光谱对所得产物进行了表征和分析。结果表明：在PEG200中放电制得的OLFs粒径均匀,石墨化程度较高;空气氧化法能提高OLFs产物的纯度;当氧气含量为20％时,表面氧化修饰效果明显。     

金属／洋葱状富勒烯的HRTEM与光学性能研究

利用金属/洋葱状富勒烯奇异的分子结构和独特的光电性能，引发世人研究采用多种方法制备富勒烯复合材料，将金属纳米微粒加入到洋葱状富勒烯的笼状中空内，用以制成具有特殊性能的纳米材料，并逐渐成为研究热点。本实验采用催化化学气相沉积法制备出了金属/洋葱状富勤烯，采用SEM和HRTEM进行结构表征，并对其荧光性能进行了分析。     

Bimorph nano actuators synthesized by focused ion beam chemical vapor deposition

Bimorph nano actuators synthesized by a two-layer focused ion beam (FIB) chemical vapor deposition (CVD) process have been demonstrated. The core bimorph segment of the actuator is a column structure made of two 200-nm thick tungsten-based-conductor (TBC) and diamond-like-carbon (DLC) layers. Several segments can be connected together of different angles to construct actuators with various moving capabilities when joule heating is applied via silicon MEMS (Microelectromechanical System) heater as the actuation source. Experimentally, a prototype five-segment actuator has shown projection displacement of 600 ± 60 nm under an input power of 1.02 W (160 mA and 6.41 V). The actuator has been repeatedly operated for over 100 times without any indication of degradation. As such, this work represents a new class of nano actuators based on versatile and flexible FIB-CVD bimorph nanostructures.     

等离子体条件下合成煤基洋葱状富勒烯的研究

洋葱状富勒烯（onion-like fullerenes OLFs）作为富勒烯类新型碳材料中的一员,因其独特的中空笼状及同心壳层结构,有望在耐磨材料、超导材料、光电材料、信息材料和生物医用材料等领域广泛应用。目前在OLFs研究中,最重要、最迫切的仍然是如何进一步开发实用、价廉的可宏量制备的方法。本文利用射频等离子体法以平朔煤为原料制备了大量较纯净的石墨化程度很高的OLFS,     

激光化学气相沉积石墨烯聚焦光斑测量研究

激光化学气相沉积(Laser Chemical Vapor Deposition,LCVD)石墨烯制备受聚焦光斑影响很大。实时检测光斑,可实现石墨烯LCVD法可控制备。设计聚焦光斑测量光学系统,提出一种基于圆拟合的改进算法检测光斑中心和半径,计算、标定光斑面积。该方法在圆拟合基础上加入了二值化、形态学处理及连通性判别等预处理方法。实验表明,该方法测得圆心位置与真值误差平均为5.58 pixel,光斑面积与真值误差平均为1.93×10-9 m2,优于传统的重心法和霍夫检测法,具有较快的计算速度和检测精度,可实现LCVD法制备石墨烯实验中聚焦光斑的非接触式测量,且对其他激光加工工艺的质量控制有借鉴意义。     

Anisotropic deposition of copper by H-assisted plasma chemical vapor deposition

In order to fill small via-holes and trenches for ultralarge scale integration (ULSI) interconnects, we propose an anisotropic chemical vapor deposition (CVD) method by which Cu is deposited at a high rate at the bottom of a trench compared to that at its side wall. The ion irradiation is the key to realize the anisotropic CVD. The anisotropy, which is a ratio of deposition rate at the bottom of a trench to that at its side wall, tends to increase with energy as well as flux of ions (H₃⁺ is the predominant ion) impinging on the substrate surface, while it does not depend on H flux. We demonstrate promising anisotropic filling of trenches by the anisotropic CVD method.     

LICVD制备纳米SiO2粉末工艺研究

对ＬＩＣＶＤ制备纳米ＳｉＯ２粉末工艺了理论分析，探索了工艺参数与粒子特征的关系，并且利用正安装置成功地制备纳米ＳｉＯ２粉末。     

激光诱导化学气相淀积初始过程的研究

分析了激光诱导化学气相淀积过程中激光对气体的激发机理，采用半经典近似的方法，推导出气体吸系数的数学表达式，以此为基础讨论了实验参量－激光强度、频率、气体压强对气体吸收过程的影响。     

常压化学气相沉积法制备SnO2微纳米材料及其催化发光性质研究

本文利用一种简单的常压化学气相沉积法在氧化石墨烯基底上制备SnO2材料.通过改变沉积参数(氯化亚锡溶液浓度和沉积时间)得到了多种形貌的SnO2微纳米材料.利用SEM,EDS和XPS对其形貌,成分及元素价态进行表征,并对SnO2材料的催化发光性能进行测试.结果表明,以该材料建立的催化发光气体传感器分别对进样2μL的甲醇,乙醇,异丙醇和丙酮展示了较高的灵敏度,快的响应速度及好的重现性.     

Epitaxial garnet films by organometallic chemical vapor deposition

Epitaxial films of Y₃Fe₅O₁₂, Eu₃Fe₅O₁₂, (Eu, Y)₃Fe₅O₁₂, and Er₃Fe₅O₁₂ l-2μm thick have been chemically vapor deposited on <111> GGG and <100> SmGG garnet substrates from 1000°C to 1200°C in an oxygen atmosphere from metal organic source compounds. These source compounds which are used here for the first time in chemical vapor deposition are tris 2, 2, 6, 6, tetramethyl 3, 5 heptanedionate complexes, (thd or M(thd)₃) of the metals used. In the reactor, the individual compounds are volatilized in a helium carrier in separate source containers. The vapors are then combined, and premixed without reaction at about 300°C with a large excess of 0₂ and passed with high velocity, ∿500 cm/sec, onto an r.f. heated substrate. The growth rate under these conditions is 0.4 - 0.8μm/hr. X-ray double diffraction, glancing angle X-ray and microprobe analyses were employed to characterize the crystallinity and stoichiometry, respectively, of the resulting garnet films. They were single crystal and exhibited a lattice constant dependent upon the rare earth to Fe ratio. The Eu containing films were not pseudomorphic probably due to the large lattice mismatch between substrate and film in most cases. The erbium iron garnet films were apparently close to pseudomorphic as determined by measured film and substrate lattice constants.     

Effects of substrate surface preparation on chemical vapor deposition growth of 4H-SiC epitaxial layers

The effects of chemical mechanical polish (CMP) and pre-growth oxidation and etching of vicinal 4H−SiC substrates on the quality of epitaxial films have been investigated. Samples with and without a collodial silica CMP and oxidation/etch treatment were studied with optical microscopy, cross section transmission electron microscopy (TEM) and atomic force microscopy (AFM) before and after chemical vapor deposition. Evidence of polishing damage was evident prior to growth in all samples without CMP treatment. Oxidation and etching appeared to generate defects by preferential etching of bulk defects such as dislocations and low angle grain boundaries. Evidence of the polishing damage remained after chemical vapor deposition (CVD) growth on the samples without CMP and the defect density was worse for the oxidized samples compared to the unoxidized ones. The unoxidized CMP wafer had the lowest defect density and rms roughness of the samples studied.