溶胶凝胶制备纳米多孔SiO2光学增透薄膜耐磨特性强化研究

在溶胶-凝胶基础上,采用碱/酸两步法和浸渍镀膜技术制备出纳米多孔SiO2薄膜,并将该薄膜在空气和氨气与水蒸气的混合气体中热处理.使用透射电子显微镜、原子力显微镜、傅立叶红外光谱仪、椭偏仪、分光光度计等分析了薄膜的特性.实验结果表明:采用碱/酸两步催化法能够明显提高纳米多孔SiO2光学增透薄膜的力学特性,混合气体中的热处理又使其力学性能得到进一步改善.薄膜耐磨等力学性能增强归因于SiO2颗粒间更多的化学键合.在力学性能增强的同时,薄膜折射率仍保持约1.24的较低值,光学增透效果良好,透射率≥99.5%.     

折射率可调疏水型SiO2光学薄膜的制备研究

以正硅酸乙酯(TEOS)为有机醇盐前驱体,采用溶胶-凝胶技术,通过控制制备条件,结合三甲基氯硅烷(TMCS)对SiO2胶粒表面的修饰过程,制备出折射率可调的疏水型SiO2薄膜.对薄膜采用了不同的后处理方式,研究了氨和水蒸气混合气体热处理技术对薄膜疏水性能的影响.采用椭偏仪、FTIR和接触角测试仪对薄膜的折射率、红外特性、接触角等的测试研究表明疏水型SiO2薄膜的折射率可在1.35～1.20之间连续可调,与传统热处理相比,混合气氛热处理使薄膜的折射率略有增加,在所研究的范围内折射率平均增加0.02左右;SiO2胶粒表面的亲水性OH基团可基本被非活性CH3基团代替,薄膜的疏水能力得到进一步提高;接触角由未作表面修饰时的40°左右增加到表面修饰并结合混合气氛热处理的137°左右.     

氨处理抑制SiO2/ZrO2薄膜膜间渗透

以正硅酸乙酯和丙醇锆为原料,用溶胶-凝胶法在K9基片上提拉镀制SiO2/ZrO2双层膜,样品1镀完SiO2后直接镀ZrO2,样品2镀完SiO2经氨处理后再镀ZrO2。研究表明,ψ和Δ两个椭偏参数的模拟值曲线与椭偏仪的测量值曲线十分吻合,进而发现氨处理可有效抑制SiO2/ZrO2双层膜之间的渗透,氨处理后渗透层减少近45nm。利用激光束对两种样品进行了损伤阈值的测试,用光学显微镜观察损伤形貌,结果发现两者损伤阈值分别为14.8和15.03J/cm2,损伤形貌均为熔融型。     

溶胶凝胶制备纳米多孔SiO2光学增透薄膜耐磨特性强化研究

在溶胶－凝胶基础上,采用碱／酸两步法和浸渍镀膜技术制备出纳米多孔SiO2薄膜,并将该薄膜在空气和氨气与水蒸气的混合气体中热处理。使用透射电子显微镜、原子力显微镜、傅立叶红外光谱仪、椭偏仪、分光光度计等分析了薄膜的特性。实验结果表明：采用碱／酸两步催化法能够明显提高纳米多孔SiO2光学增透薄膜的力学特性,混合气体中的热处理又使其力学性能得到进一步改善。薄膜耐磨等力学性能增强归因于SiO2颗粒间更多的化学键合。在力学性能增强的同时,薄膜折射率仍保持约1．24的较低值,光学增透效果良好,透射率≥99．5％。     

SiO2气凝胶常压制备、表面结构与吸附性质

采用溶胶-凝胶技术,以多聚硅（E-40）为源,通过表面修饰工艺,在常压条件下制备了SiO2气凝胶.采用扫描电镜、13C和29Si核磁共振谱以及孔径分布仪对SiO2气凝胶的微结构进行了表征,并用微量电子真空吸附天平对SiO2气凝胶的吸附特性进行了研究.结果表明：SiO2气凝胶具有纳米多孔结构、较好的疏水和亲水可调性,是一种极好的高吸附材料.     

低折射率SiO2光学增透薄膜的结构控制

以正硅酸乙酯（ＴＥＯＳ）为有机硅源,采用溶胶－凝胶技术,通过调节溶胶的ｐＨ和掺入有机添加剂,对ＳｉＯ２溶胶生长过程进行了结构裁剪,控制ＳｉＯ２纳米颗粒尺度,制备出低折射率（１．１５～１．１８）ＳｉＯ２光学增透薄膜,分别采用椭偏仪,分光光度计,扫描和透射榻镜等对所制备薄膜的结构,物性进行研究,研究结果表明,改变ＳｉＯ２溶胶ｐＨ可有效抑制颗粒生长,且保持原有微结构;掺入有机偶联添加剂能使颗粒迅速增大。     

水热法制备ZrO2高折射率薄膜

以 Ｚｒ Ｏ Ｃｌ２·８ Ｈ２ Ｏ 为原料，采用水热法和溶胶凝胶工艺制备颗粒度为几至几十纳米的 Ｚｒ Ｏ２水溶胶，再以甲氧基乙醇转换为醇溶胶，用旋转镀膜法制备了高折射率 Ｚｒ Ｏ２ 薄膜。应用原子力显微镜及台阶仪测试了膜表面微观形貌，获得了膜的红外光谱，并用椭偏仪测得薄膜厚度与折射率。研究了薄膜厚度、折射率与热处理温度的关系，并就有机粘接剂 Ｐ Ｖ Ｐ 对 Ｚｒ Ｏ２ 薄膜折射率及机械强度的影响作了初步探讨。     

紫外辐照对溶胶-凝胶光学薄膜性能的影响

采用溶胶-凝胶技术,使用旋涂方法在K9玻璃和单晶硅片上制备各种光学薄膜,并用紫外光源作为高能光子源辐照溶胶-凝胶光学薄膜。使用扫描电镜(SEM)、原子力显微镜(AFM)、椭偏仪、铅笔硬度仪等测量和分析薄膜的特性。用输出波长1 064 nm、脉宽15 ns电光调Q激光系统测试薄膜的激光损伤阈值。结果表明,紫外光辐照可提高薄膜折射率和机械性能。采用紫外预处理还能将节瘤缺陷转换成孔洞缺陷,从而有效提高薄膜的激光损伤阈值,其中,单层ZrO2薄膜的激光损伤阈值达到50.6 J/cm2(1 064 nm,1 ns)。与当前流行的激光预处理技术相比,紫外预处理的设备简单、易于操作。溶胶-凝胶多层膜经紫外光处理后,有效提高了多层膜膜层的均匀性。     

惯性约束聚变靶材料碳气凝胶的制备方法

用溶胶-凝胶法制备出了高RC比(间苯二酚与催化剂的摩尔比)的RF有机气凝胶,通过溶剂替换,成功地实现了常压条件下的干燥工艺.经高温碳化处理,将RF有机气凝胶转化为碳气凝胶,改变RC比和聚合单体的质量百分数,可控制气凝胶的粒径及孔径、密度及比表面积.用扫描电镜(SEM)、BET等方法对其颗粒大小、密度、比表面积及孔径分布等微结构进行了分析测试.制备出的碳气凝胶性能满足惯性约束聚变靶材要求.     

高效X光背光源靶材料的研究进展

靶材料的成分、微结构和密度是决定激光驱动X光背光源光子能量和强度的关键参数。基于此,介绍了背光源靶的分类、靶材料的制备及其与强激光的作用机制。背光源靶有着由稠密靶向欠稠密靶发展的趋势,其中,泡沫疏松靶以其操作安全和可选成分广泛等优点成为高效欠稠密靶。泡沫疏松靶材料又包含纳米纤维和气凝胶：纳米纤维是由静电纺丝结合热处理工艺制备的,具有成型性好、发光原子含量高等特点;而气凝胶靶则通过溶胶-凝胶技术结合超临界流体干燥工艺制备,其微结构均匀、理论转换效率高,但目前合成条件复杂、发光原子含量较低。结合多种溶胶-凝胶技术合成密度低、发光原子含量高的块体气凝胶将成为背光源制靶重要的研究方向。     

SiO2(am)在FoCa粘土和MX-80粘土中扩散实验的模拟

不定形二氧化硅[Amorphous Silica，简称SiO2（am）]是高放废物玻璃固化体在处置后，发生降解的主要产物。对SiO2（am）在FbCa粘土和MX-80粘土柱中的扩散迁移进行了实验研究，结果显示：在粘土柱中有大量的SiO2（am）沉淀产生；土柱中总Si增加量与时间的关系基本为线性正相关关系。采用CRUNCH程序对上述扩散迁移实验进行了模拟，模拟内容包括：溶液和岩相中Si浓度变化、总的筋增加量与时间的关系以及实验期间孔隙率的变化；同时分析了有效扩散系数对结果的影响。结果说明，使用CRUNCH程序进行反应迁移模拟是可行的；但是实验中pH值测量时机不适当；另外由于土样本身Si含量较高，易对土柱总Si的分析结果产生影响，这些因素需进一步实验时改进。     

Elastic behaviour of titanium dioxide films on polyimide substrates studied by in situ tensile testing in a X-ray diffractometer

The development of new devices has created needs of precision, conformal at the atomic level deposition of high quality thin film materials. In the last years, Atomic Layer Deposition (ALD) has received much interest as a potential deposition method for advanced thin film structures. ALD presents several advantages: the film is excellently conformal and reproducible; the film thickness depends only on the number of reaction cycles, which makes the thickness control accurate and simple; the film can be deposited onto all kind of substrates. Because of the process slowness, layer thickness is generally less than 100 nm. This makes more difficult to study all characteristics of the coating. Thin layers deposited onto bulk substrates are generally in tensile or compressive stress state, which may significantly affect physical properties and possibly compromise their lifetime. To determine the residual stress it is mandatory to know the elastic constants that may also depend on the microstructure of the layers and thus the deposition process.In this work, 2D X-ray diffraction (XRD²) in combination with in situ tensile testing has been applied for the first time to measure elastic properties of TiO₂ anatase films obtained by ALD. Experimental conditions, the tensile stage being installed in a laboratory micro-diffractometer equipped with a 2D image-plate detector, and the information that can be extracted from 2D diffraction patterns will be discussed. Based on these preliminary results, synchrotron radiation beam time has been allocated to study elastic properties of these thin films. The advantages and disadvantages of the proposed laboratory equipment, with respect to the synchrotron beam lines, are discussed.     

磁过滤阴极真空弧法制备纳米nc-ZrCN/a-C:H(N)复合薄膜

采用磁过滤阴极弧法,以金属zr为阴极在真空室中通人C2H2和N2混合气体来制备纳米nc-ZrcN/a-c:H(N)复合薄膜,用X射线衍射(XRD)、扫描电镜的能谱仪(SEM-EDS)、X射线电子能谱(XPS)和纳米力学探针研究了薄膜的成分、结构及其性能.实验结果表明薄膜是由ZrCN和无定形碳两种纳米结构组成;气体流速对复合膜的的成分和结构有显著影响:随着混合气体流速的增加,薄膜的锆原子百分比减小,而N和C的含量逐渐增大,薄膜的硬度逐渐减小,ZrCN峰强度逐渐降低.     

Optical Characterization of Amorphous Hydrogenated Carbon(a-C:H)Thin Films Prepared by Single RF Plasma Method

Methane(CH4) plasma was used to produce amorphous hydrogenated carbon(aC:H) films by a single capacitively coupled radio frequency(RF) powered plasma system.The system consists of two parallel electrodes:the upper electrode is connected to 13.56 MHz RF power and the lower one is connected to the ground.Thin films were deposited on glass slides with different sizes and on silicon wafers.The influence of the plasma species on film characteristics was studied by changing the plasma parameters.The changes of plasma species during the deposition were investigated by optical emission spectroscopy(OES).The structural and optical properties were analyzed via Fourier transform infrared(FTIR) spectroscopy,X-ray diffraction(XRD) and UV-visible spectroscopy,and the thicknesses of the samples were measured by a profilometer.The sp~3/sp~2 ratio and the existing H atoms play a significant role in the determination of the chemical properties of thin films in the plasma.The film quality and deposition rate were both increased by raising the power and the flow rate.     

Recovery of Heat-Generating Nuclides in Eluted Solutions

To study about microstructure and chemical composition of oxide films formed on surface of stainless steel is most important for understanding of stress corrosion cracking (SCC) and irradiation assisted stress corrosion cracking (IASCC). In this work, a new sample preparation method for microstructure observation of oxide films was developed. To prevent to break oxide films during fabrication, surface of specimens were protected with plating. Focused ion beam (FIB) processing was conducted to prepare thin foil samples of cross section of oxide films. After sample preparation, microstructure of cross section of oxide films was observed by transmission electron microscope (FE-TEM), and microscopic chemical composition was analyzed by energy dispersed X-ray spectrometer (EDS). From the results, effects of silicon (Si) doping for oxide film formation in two oxidation conditions are discussed.     

离子束增强沉积法制备Mo2N和Mo2-xTixN薄膜及其结构与性能研究

分别采用氮离子束增强沉积和Ｎ－Ｔｉ离子束同步增强沉积工艺制备了Ｍｏ２Ｎ和Ｍｏ２－ｘＴｉｘＮ薄膜,用ＸＲＤ,ＴＥＭ、划痕和阳极极化方法研究了两者的结构与性能。     

Microwave Plasma Chemical Vapor Deposition of Diamond Films on Silicon From Ethanol and Hydrogen

Diamond films with very smooth surface and good optical quality have been deposited onto silicon substrate using microwave plasma chemical vapor deposition(MPCVD)from a gas mixture of ethanol and hydrogen at a low substrate temperature of 450℃.The effects of the substrate temperature on the diamond nucleation and the morphology of the diamond film have been investigated and observed with scanning electron microscopy(SEM).The microstructure and the phase of the film have been characterized using Raman spectroscopy and X-ray diffraction(XRD).The diamond nucleation density significantly decreases with the increasing of the substrate temperature.There are only sparse nuclei when the substrate temperature is higher than 800℃ although the ethanol concentration in hydrogen is very high.That the characteristic diamond peak in the Raman spectrum of a diamond film prepared at a low substrate temperature of 450℃ extends into broadban indicates that the film is of nanophase.No graphite peak appeared in the XRD pattern confirms that the film is mainly composed of SP^3 carbon.The diamond peak in the XRD pattern also broadens due to the nanocrystalline of the film.     

Formation of Au nanoparticles in silica by post-irradiation and thermal annealing

SiO₂ + Au thin films were prepared on SiO₂ substrates using ion beam assisted deposition (IBAD). The film was annealed at different temperatures. After each annealing, the optical absorption spectrum was taken to monitor the gold nanocluster formation in the thin film. By using Doyle’s formula, the size of the nanoclusters was determined and plotted as a function of the annealing temperature. Separately, other identical films were bombarded with ions of different energies and different fluence to monitor the nanoclusters forming during the bombardments. We have compared the effect of electronic energy deposition of the energetic ions with the effect of annealing at various temperatures.     

Improved high energy microbeam techniques

The University at Albany ion scanning microprobe has been used for many industrial applications in thin films. Of prime importance for rapid analysis, the beam should be set-up and in-use very shortly after the beam is turned on. Rapid optical and electronic tune-up methods are discussed. Standard 1–2 micron, 2 MeV helium or proton beams are generally used with RBS (Rutherford Backscattering) and PIXE (Particle Induced X-ray Emission) to obtain composition analysis in one- or two-dimensions. We demonstrate the use of 3-dimensional analysis in thin films, wherein film thickness is the third dimension.