【作者】 陈泉水；

【导师】 高后秀；

【作者基本信息】 天津大学 ， 材料学， 2005， 博士

【摘要】 固体“类流态”是固体表面及其内部存在的一种类似于流体的状态,是一种除气、液、固、液晶之外的一种新的物质存在形式。本文利用金相显微镜、原子力显微镜、X射线衍射仪、扫描电镜、透射电镜等观测仪器对纯金属、合金和非金属材料糜棱状石英岩、辉长岩等进行观察,验证了在常温常压下,这些材料中存在着一种未被人们认知的,具有类似流体特征的非线性振荡现象——“类流态”现象,这是一种非极端条件下新的物质存在状态。其普遍存在于各类固体物质中,当外界条件达到类流态胞区出现的临界值时,固体中就会出现这种状态。“类流态”的宏观表现为材料表面观察到动态的运动并可测量到某些性能的变化,微观表现为用高倍数的仪器进行测量时可以发现点阵结构的变化和X射线衍射谱线的细微波动。将小尺度和大尺度范围内的测量结果进行比较,发现“类流态”现象呈现出典型的分形特征,即局部上显示出无规律性、随机性,而在整体上呈现自相似性。固体“类流态”的振荡过程是一种典型的非线性动力学过程。准一维纳米结构材料,包括纳米管、纳米线(棒)、以及复合纳米线(纳米同轴电缆、异质结等),在未来纳米器件中的连接、场发射平板显示、能量存储以及高强度复合材料上,均具有潜在的应用前景。目前有关准一维纳米材料的研究已经成为物理、化学及材料学等学科开展工作的重点。其中,准一维纳米材料的制备则是开展准一维纳米材料研究的前提和基础。本文工作的重点是研究新型准一维纳米结构材料的合成、生长的控制和机理的探索。本文首次报道以Cu-Zn-Al合金为基体,在常温常压非真空条件下制得了一系列全新的一维合金纳米结构包括合金纳米管、合金纳米线、合金纳米棒以及分散的零维合金纳米颗粒。随后,通过大量的条件实验摸索合金纳米结构的制备工艺,发现在常温常压下通过HNO3、HCl、H3PO4、HAC按不同比例构成的混合酸处理退火态Cu-Zn-Al合金可以制得合金纳米结构,同时通过大量对比实验排除了双喷电解抛光和离子减薄过程可能对合金纳米结构的生成起作用的怀疑。采用透射电镜、扫描形貌分析、选区衍射、能量分散X射线分析等对制得的纳米结构进行了表征。所得合金纳米管外径为40nm左右,内径从几纳米到十几纳米不等,有顶端被纳米颗粒封闭的形貌,也有顶端开口的形貌;合金纳米线及纳米棒直径在10nm-40nm范围内变化,最大长度可达数微米;合金纳米颗粒的粒径为更多还原

【Abstract】 Solid quasi-fluid state, which is similar to liquid and exists in surface and interiorof solid, is one new kind of state besides gas, liquid, solid and liquid crystal. In thispaper, the phenomenon which is similar to liquid is validated under normaltemperature and pressure on the surface of pure metal, alloy, mylonitic quartzite,gabbros et al. using metallographic microscope, AFM, X-ray diffractometer, SEM andTEM. The phenomenon reveals a new matter existence state in non-extreme arduousconditions, and the ubiquity is one of its most important characteristics. When theexternal condition reaches the critical value, the phenomenon will appear in solids.In macroscopic scale, the dynamical motion can be observed and someperformance changes can be measured in quasi-fluid state cell. Under high powermicroscope, the lattice structure changes can be observed, the X-ray diffractionspectral lines exhibit fine fluctuation. Comparing the small-scale results with the greatones, the irregularity and randomicity appear in local, and the self-comparability isshowed as a whole, i.e. ‘quasi-fluid state’ presents a typical fractal character, which isa typical nonlinear dynamical system.Quasi-one dimensional (1D) nanomaterials such as nanotubes, nanowires orcomposite (nanocables, nano-heterojunctions) has become the most active areas inphysics, chemistry and materials research due to their potential applications in theconnects of electric or photoelectric nanodevices, field emission panel display, energystorage, and high-strength composites. Among them, the effective synthesis of one-dimensional nanomaterials has always been the research focus related to the one-dimensional nanomaterials. In this thesis, we present our work mainly involved thesynthesis of novel one-dimensional nanomaterials, their growth mechanism and alsoproperties explored.Herewith, Cu-Zn-Al shape memory alloy is a kind of function material with fineperformance and low cost. When we studied it, some new one dimensional alloynano-structures were attained including alloy nanotubes, alloy nanowires, alloynanorodes, and some zero dimension separated alloy nanoparticals in normaltemperature and pressure . Through a mass of experiments, it was found that the alloynano-structures would be attained when the annealed Cu-Zn-Al alloy was treated bymixed acid include HNO3, HCl, H3PO4, HAC. And it was confirmed that twin-jetelectrolytic polishing and ionization had nothing to do with growth of alloynano-structures by large number of experiments. The alloy nano-structures wereattributed by TEM, SEM and EDX. The outer diameter of nanotubes were about40nm, and their inner diameter were from 10nm to 40nm. The top end of somenanotubes were enclosed by nanoparticals and the others top end were open. Thediameter of nanowires and nanorods were from 10nm to 40nm, and the most length ofnanowires and nanorods were over micron. The grain size of nanoparticals were from10nm to 40nm, and their dispersity were fine. The main ingredients of alloynano-structures were Cu, Zn and Al, and the structures of them were polycrystal.In the process of researching growth mechanics of alloy nano-structures, it wasconfirmed that ‘quasi-fluid cell’, a kind of non-liner oscillation phenomenon in the alloy,was the critical factor. The alloy atoms motion rules of cell were researched deeply bymetallographic, SEM, TEM, AFM, X-ray and so on. According to the experimentaldata, the chaotic movement of the quasi-fluid cell oscillation thim series in solid isanalyzed, The dynamical system phase space was reconstructed;the systemparameters were calculated, such as Lyapunov exponents, Kolmogorov entropy, andHurst exponents. The results proved that the quasi-fluid is a very complex activity,and it is an obvious process from chaos into order. According to the characters ofquasi-fluid cell such as chaotic, self-organizing and similarity with fluid, the questionsabout where the energy and atoms which composing alloy nano-structures come from,how the alloy nanotubes nucleate and why the atoms can grow directionly could beexplained reasonably. So the grow model of one dimensional alloy nano-structureswere put forward in response to quasi-fluid state.Silicon-based materials have the research focus of semiconductor industry. Inchapter five, a novel method has been developed to produce bulk quantities of siliconnanowires. Encouraging results shows that thesis 1D nanomaterials should havepotential in opto-electric nanodevices in the future. In addition, the alternative methodcould be explored for the synthesis of other 1D nanomaterials.With all successes and failure related to the synthesis of 1D nanomaterials, we getmore knowledge and understanding to the growth mechanics of 1D nanomaterialsbased on Cu-Zn-Al alloy.更多还原