微波CVD法合成金刚石薄膜的生长规律

用微波等离子化学气相沉积方法（ＣＶＤ片）用丙酮－氢气混合气体作为原料,在单晶硅的（１１１）面和人造单晶金刚石的（１００）面上,生长出了优质金刚石薄膜,并对薄膜的生长规律进行了研究。     

真空共蒸发法沉积的ZnTe：Cu薄膜

用真空共蒸发法沉积了ＺｎＴｅ和ＺｎＴｅ：Ｃｕ多晶薄膜,研究了Ｃｕ含量对薄膜结构和电学性能的影响。发现刚沉积的ＺｎＴｅ薄膜和轻掺杂的ＺｎＴｅ：Ｃｕ薄膜的结构均为高度（１１１）择优取向的立方相。掺杂浓度较高的ＺｎＴｅ：Ｃｕ薄膜除了立方相外,还存在六方相。重掺杂薄膜中（１１１）择优取向消失。在ＺｎＴｅ：Ｃｕ薄膜中观察到反常的暗电导温度关系曲线。薄膜的光学能隙在２．１５～２．２１ｅＶ之间。用结构相变的观点对实验现象作了解释。     

微波等离子体CVD金刚石薄膜的显微结构

用扫描电镜（ＳＥＭ）和透射电镜（ＴＥＭ）对６种微波等离子体ＣＶＤ金刚石薄膜的表面形貌和显微结构进行了研究，结果表明：在金刚石晶粒长大过程中，（１１１）面方向长大时产生密度很高的微挛晶缺陷，而（１００）面方向长大时产生的晶体缺陷较少。     

多弧离子法制备的Ti（C,N）膜微结构随C2H2／N2流量比变…

用多弧离子法在高速钢（Ｗ１８Ｃｒ４Ｖ）基底上沉积了Ｔｉ（Ｎ，Ｃ）薄膜，并运用ＳＥＭ、ＸＲＤ、ＸＰＳ对该膜微观结构随进气流量ｒ＝Ｇ２Ｈ２／Ｎ２变化的情况进行了测试和分析。结果表明薄膜随ｒ增加趋于致密，在ｒ值较小时呈现较强的（１１１）择优取向，随着ｒ值增大，（１１１）是这一取向逐渐变弱，（２２０）取向渐强，薄膜呈现典型耐心立方结构，主要万分为复合相Ｔｉ（ｎ，Ｃ）膜含有少量石墨相成分存在。     

Si（111）表面离子束辅助沉积对类金刚石薄膜结构影响的计算机模拟

本文选C2分子和Ar离子作为沉积源和辅助沉积粒子,采用分子动力学（MD）方法在Si（111）面上模拟研究了离子束辅助沉积（IBAD）类金刚石（DLC）膜的物理过程.重点讨论了C2分子和Ar离子的入射能量及到达比（Ar/C）对平均密度和sp^3键含量的影响,并与Si（001）-（2×1）表面生长类金刚石膜的结果进行比较.结果表明,到达比和入射能的改变,对薄膜结构的影响不同;Si（111）面上生长类金刚石膜,薄膜在衬底的附着力更强.     

WC—Co硬质合金刀片热丝法金刚石薄膜涂层附着力

用热丝法研究了ＷＣ－６％Ｃｏ硬质合金刀片金刚石薄膜涂层附着力。结果表明：采用温度为８０℃,（ＨＣｌ：ＨＮＯ３：Ｈ２Ｏ）（体积比）为１∶１∶１溶液对硬质合金刀片表面去Ｃｏ１５ｍｉｎ后,经４０ｕｍ金刚石粉及１．５ｕｍ金刚石加２０ｕｍＴａＣ混合粉进行超声预处理,结果表明,沉积的金刚石薄膜与硬质合金刀片基底具有良好的附着力,而经４０ｕｍ金刚石粉处理的薄膜涂层组织与附着力要好一些。     

氢原子在Cu,Pt（100）,（111）,（110）面上的吸附扩散势能面结…

构成了Ｈ－Ｃｕ，Ｈ－Ｐｔ相互作用的５参数Ｍｏｒｓｅ势、用经典的对势 氢原子在Ｃｕ（１００），Ｃｕ（１１１），Ｃｕ（１１０），Ｐｔ（１００），Ｐｔ（１１１），Ｐｔ（１１０）面上的吸附和扩散，得到了氢原子在６个表面上的吸附位，吸附几何，键能及本征振动等数据和实验结果附和得很好。     

衬底负偏压热灯丝CVD金刚石薄膜在锥体上核化的研究

以ＣＨ４和Ｈ２为反应混合气体,用衬底负偏压热灯丝ＣＶＤ法在Ｓｉ（１００）面上制备金刚石膜,使用扫描电子显微镜（ＳＥＭ）,Ｒａｍａｎ谱和Ｘ射线光电子能谱（ＸＰＳ）对在硅尖上的金刚石核化进行了研究,并着重讨论了沉积在硅尖上的金刚石颗粒的生长机理。     

掺氮类金刚石薄膜(α-C:H:N)显微结构的研究

用射频等离子体化学气相沉积法（ＲＦ－ＣＶＤ）和ＣＨ４、Ｎ２与Ａｒ组成的混合气体制备掺氮类金刚石薄膜（α－Ｃ：Ｈ：Ｎ）。用原子力显微镜（ＡＦＭ）、俄歇电子能谱（ＡＥＳ）、红外光谱（ＩＲ）以及显微拉曼谱（Ｍｉｃｒｏ－Ｒａｍａｎ）对α－Ｃ：Ｈ：Ｎ薄膜的表面形貌、组分和微观结构进行表征。实验结果表明,薄膜中有纳米量级的颗粒存在,而且随反应气体中Ｎ２与ＣＨ４比值的增大,薄膜中的氮元素含量也随之增大,并主要以     

单源低能离子束辅助沉积类金刚石薄膜摩擦性能研究

采用单源低能离子束辅助沉积的方法，制备了非晶碳薄膜，分别用喇曼光谱，俄歇电子能谱了薄膜的结构，薄膜为无定形的类金刚石薄膜，薄膜中石墨键（ＳＰ＾２）所占的比重较大，沉积时随着离子束能量及束流的增加，薄膜的显微硬度，摩擦系数，摩擦寿命均增加，类金刚石薄膜具有较好的摩擦性能。     

直流辉光放电等离子体增强化学气相法制备金刚石及氮化碳薄膜

采用直流辉光放电等离子体增强化学气相沉积(PECVD)技术方法 ,在Si(100)衬底上制备了金刚石薄膜 ,并在此基础上合成了含有少量晶态颗粒的非晶氮化碳薄膜     

纳米金刚石粉末电化学性能及其表面修饰的研究进展

对导电金刚石电极的研究,过去主要集中在化学气相沉积(CVD)制备的含硼金刚石薄膜电极领域。近来有研究表明当金刚石薄膜晶粒尺寸达到纳米级时,无需掺杂硼,金刚石也表现出一定的电导率。本课题组研究发现非掺杂的纳米金刚石粉末在水溶液中也表现出了一系列的电化学活性。本文介绍了非掺杂纳米金刚石的电化学性能及其对亚硝酸根离子的催化氧化行为,另外还介绍了对纳米金刚石进行表面修饰以提高其电化学活性,增加它在电化学领域的应用范围等方面的研究进展。     

单晶金刚石在铁基合金中的性态与行为

将金刚石单晶孕镶在Ｆｅ基合金中，在一定条件下烧结，发现金刚石受到明显刻蚀，但晶体结构和强度未变，刻蚀在金刚石与结合剂的界面发生，它是金刚石晶格中的Ｃ原子溶入Ｆｅ，并在其中扩散的过程，适当控制这一扩散过程，将使Ｆｅ基结合剂的金刚石工具获得优良性能。     

Conversion of silicon carbide to crystalline diamond-structured carbon at ambient pressure

Synthetic diamond is formed commercially using high-pressure, chemical-vapour-deposition and shock-wave processes, but these approaches have serious limitations owing to low production volumes and high costs. Recently suggested alternative methods of diamond growth include plasma activation, high pressures, exotic precursors or explosive mixtures, but they suffer from very low yield and are intrinsically limited to small volumes or thin films. Here we report the synthesis of nano- and micro-crystalline diamond-structured carbon, with cubic and hexagonal structure, by extracting silicon from silicon carbide in chlorine-containing gases at ambient pressure and temperatures not exceeding 1,000 degrees C. The presence of hydrogen in the gas mixture leads to a stable conversion of silicon carbide to diamond-structured carbon with an average crystallite size ranging from 5 to 10 nanometres. The linear reaction kinetics allows transformation to any depth, so that the whole silicon carbide sample can be converted to carbon. Nanocrystalline coatings of diamond-structured carbon produced by this route show promising mechanical properties, with hardness values in excess of 50 GPa and Young's moduli up to 800 GPa. Our approach should be applicable to large-scale production of crystalline diamond-structured carbon.     

Analysis of the carbon source for diamond crystal growth

The lattice constants of diamond and graphite at high pressure and high temperature （HPHT） were calculated on the basis of linear expansion coefficient and elastic constant. According to the empirical electron theory of solids and molecules （EET）, the valence electron structures （VESs） of diamond, graphite crystal and their common planes were calculated. The relationship between diamond and graphite structure was analyzed based on the boundary condition of the improved Thomas-Fermi-Dirac theory by Cheng （TFDC）. It was found that the electron densities of common planes in graphite were not continuous with those of planes in diamond at the first order of approximation. The results show that during the course of diamond single crystal growth at HPHT with metal catalyst, the carbon sources forming diamond structure do not come from the graphite structure directly. The diamond growth mechanism was discussed from the viewpoint of valence electron structure.     

Mechanism of diamond-to-graphite transformation at diamond-stable conditions

The diamond-to-graphite transformation at diamond-stable conditions is studied by temperature gradient method （TGM） under high pressure and high temperature （HPHT）, although it is unreasonable from the view of thermodynamic considerations. It is found that, at diamond-stable conditions, for example, at 5.5 GPa and 1550 K, with fine diamond grits as carbon source and NiMnCo alloy as metal solvent assisted, not only large diamond crystals, but metastable regrown graphite crystals would be grown by layer growth mechanism, and the abundance of carbon source in the higher temperature region is indispensable for the presence of metastable regrown graphite crystals. From this transformation, it is concluded that, with metal solvent assisted, although the mechanism of crystal growth could be understood by the macro-mechanism of solubility difference between diamond and graphite in metal solvents, from the point of micro-mechanism, the minimum growth units for diamond or graphite crystals should be at atomic level and unrelated to the kinds of carbon source （diamond or graphite）, which could be accumulated free-selectively on the graphite with Sp2Tr or diamond crystals with sp3 bond structure.     

用热解CVD方法合成的金刚石的结晶特性

本文研究了用热解CVD方法合成的金刚石的结晶特性,并与用高温高压法合成的金刚石的结晶特性做了比较。     

Variations in carbon isotopic composition in the subcontinental lithospheric mantle beneath the Yangtze and North China Cratons: Evidence from in-situ analysis of diamonds using SIMS

The components and evolution of subcontinental lithospheric mantle beneath the North China Craton and the Yangtze Craton is a current topic in the geological study of China and the carbon isotopic composition of diamond is one of the most direct probes into cratonic lithospheric mantle processes.In this paper,in-situ SIMS(Secondary Ion Mass Spectrometry) techniques were used to analyze the carbon isotope compositions at different internal growth zones of diamonds from Shandong and Liaoning in the North China Craton and Hunan in the Yangtze Craton.It was found that the carbon isotopic range of diamonds from the North China Craton are rather distinct from those of the Yangtze Craton;the former has a range of 6.0‰ to 2.0‰(relative to VPDB) with an average value of 3.0‰ in their core areas,which is consistent with global peridotitic diamonds;the diamonds from the Yangtze Craton,however,have a carbon isotopic range from 8.6‰ to 3.0‰ with an average value of 7.4‰ in their core areas,being more consistent with global eclogitic diamonds.The variations of carbon isotope ratios between different internal growth zones in individual diamonds were different in the three diamond localities studied.There was a clear correlation between changes in carbon isotopic composition and phases of diamond dissolution and new growth,while no correlation was observed between δ13C and internal inclusions.The variations suggest that the carbon isotopic compositions of mantle fluids were changing during the process of diamond crystallization,and that the heterogeneity of the carbon isotopic composition in mantle carbon reservoirs was a more important factor than carbon isotope fractionation in controlling the carbon isotopic compositions and their variation in diamonds.In addition,the preliminary results of in-situ nitrogen analyses demonstrated that the variation of carbon isotopic compositions between the core and outer growth zones does not correlate with nitrogen abundances,implying either that diamonds crystallized in an open environment or that the carbon isotopic composition and nitrogen contents in mantle fluids were controlled by other,not yet understood factors.The experimental results provide hints that the isotopic composition of carbon and its original sources were different in metasomatic fluids controlling diamond formation in the mantle beneath the North China Craton and the Yangtze Craton.     

碳源浓度对掺硼金刚石/多孔钛复合材料制备的影响

利用热丝化学气相沉积技术,在多孔钛膜上生长重掺硼金刚石薄膜,研究了碳源浓度对复合膜表面形貌及薄膜质量的影响.结果表明钛膜表面沉积的掺硼金刚石薄膜因碳源浓度的不同而不同,掺硼金刚石薄膜的质量随碳源浓度的减小而提高.金刚石/钛复合膜因碳源浓度的不同会产生复杂的变化,在重掺杂高碳源浓度下金刚石生长抑制碳化钛的形成.     

Selective interfacial bonding and thermal conductivity of diamond/Cu-alloy composites prepared by HPHT technique

Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature (HPHT) sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding strength and thermo-physical properties of the composites were achieved using an atomized copper alloy with minor additions of Co, Cr, B, and Ti. The thermal conductivity (TC) obtained exhibited as high as 688 W·m-1·K-1, but also as low as 325 W·m-1·K-1. A large variation in TC can be rationalized by the discrepancy of diamond-matrix interfacial bonding. It was found from fractography that preferential bonding between diamond and the Cu-alloy matrix occurred only on the diamond {100} faces. EDS analysis and Raman spectra suggested that selective interfacial bonding may be attributed to amorphous carbon increasing the wettability between diamond and the Cu-alloy matrix. Amorphous carbon was found to significantly affect the TC of the composite by interface modification.