UO2表面铝薄膜生长过程的AES原位研究

室温下在俄歇电子能谱(AES)分析仪超高真空室中,通入适量O2,促使基底U表面氧化,生成UO2,然后利用Ar+枪溅射铝箔,使铝沉积在UO2表面形成Al薄膜.沉积过程中实时采集UO2表面的AES谱和低能电子损失谱(EELS),原位分析铝薄膜在UO2表面的生长过程和膜间界面反应.研究表明,室温下, UO2表面的铝薄膜以岛状方式生长;铝与UO2之间存在相互作用,电子从铝原子向UO2中的铀离子转移,由于表面吸附氧的作用,在UO2/Al界面处存在少量的Al2O3;沉积Al原子与UO2之间发生明显的扩散行为,铝向UO2中扩散,形成了一个氧化态铀、金属铀和铝三者共存区.     

离子镀膜法制备铀薄膜的表征

研究了离子镀膜法制备铀薄膜的性质,可为改善薄膜性能、完善过程模型、优化制备参数和提高制备效率提供依据。本工作通过扫描电子显微镜和X射线衍射分别测量了离子镀膜法制备铀薄膜的表面形貌和物相结构,通过俄歇电子能谱和X射线光电子能谱结合Ar+溅射深度剖析,对离子镀膜法制备铀薄膜的元素成分、化学形态及纵深方向的分布进行了分析。分析结果表明:制备的铀薄膜在基体上分布连续,主要物相为CaF2类型面心结构UO2,主要形态为UO2、金属U和FeUO4化合物。     

多台阶光栅结构的溶胶凝胶法制备工艺

采用溶胶凝胶法制备一种具有光敏性的ZrO₂薄膜,通过紫外分光光度计对薄膜曝光前后的结构变化进行分析。结果表明,该薄膜具有良好的光敏性。采用紫外曝光结合图形转移工艺,制备了具有多台阶结构的复杂微细图形。测量结果表明,该结构为周期性三台阶结构,周期为210μm,每个台阶的高度约为325nm。     

多层介质/金属紫外滤光膜系的辐照损伤特性

利用电子束蒸发方法制备用于BaF₂晶体慢成分滤光的多层介质/金属紫外滤光膜系。在γ射线、中子和激光辐照环境中研究薄膜的损伤特性。结果表明：薄膜对γ射线和中子具有优良的耐辐照特性；在激光辐照环境中，薄膜的激光损伤阈值受多层薄膜中金属层的影响，激光入射时，最先辐照到的金属层的厚度决定了多层薄膜的耐激光辐照损伤特性。     

乙异羟肟酸与Zr(Ⅳ),UO2+2配合物稳定常数的测定

对乙异羟肟酸(AHA)与Zr(Ⅳ), UO2 2的配位行为进行了初步研究,测定了AHA与Zr(Ⅳ), UO2 2配合物的稳定常数.结果表明,在HClO4体系中,AHA与Zr(Ⅳ), UO2 2分别发生三、二级配位,其稳定常数分别为:β1(Zr(Ⅳ))=(6.7±0.1)×1013,β2(Zr(Ⅳ)) =(1.8±0.1)×1025,β3(Zr(Ⅳ))=(3.8±0.3)×1035;β1(UO2 2)=(8.6±0.4)×107,β2(UO2 2)=(3.8±0.1)×1014.     

有序介孔氧化硅薄膜制备及其TiO2组装

采用正硅酸乙酯（TEOS）作硅源，分别以阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）和两亲性三嵌段共聚物（EO₂₀PO₇₀EO₂₀）为模板剂，盐酸为催化剂，利用溶胶凝胶工艺（sol-gel），通过提拉法在常压下制备介孔氧化硅薄膜。XRD和TEM测试结果表明,介孔氧化硅薄膜具有高度有序性。分别以这两种薄膜为模板，通过向模板内压入TiCl₄液体，并用水解、高温热处理等方法，合成了直径为50~300nm的纳米TiO₂纤维，并用SEM对其进行了表征。纳米TiO₂纤维并不能形成于未去除模板剂的薄膜或未镀膜的基底上。纳米TiO₂纤维的形貌可通过调节介孔氧化硅薄膜的孔径大小来控制。经200~600℃高温热处理后，纳米TiO₂纤维呈锐钛矿结构。随着热处理温度升高，纳米TiO₂纤维的晶化程度增加。     

电子束辐照制备Pd/TiO2光催化薄膜

用电子束辐照浸泡在浓度分别为1×10-5、1×10-4、1×10-3、1×10-2和1×10-1mol/L的PdCl2溶液中的TiO2薄膜,在TiO2薄膜表面形成Pd纳米颗粒.通过X射线衍射(X-ray diffractometry,XRD)、场发射扫描电镜(Field emission scanning electron microscope,FESEM)、X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)和紫外可见(Ultraviolet visible,UV-Vis)吸收光谱对辐照后的Pd/TiO2薄膜进行表征.分析表明,TiO2薄膜表面上沉积了直径20-50 nm的颗粒,为面心立方结晶的金属Pd;Pd/TiO2薄膜的UV-Vis光谱吸收边向可见光方向发生了偏移.用甲基橙作为光催化降解反应物,研究了Pd/TiO2薄膜分别在紫外光、可见光作用下的光催化降解效率.结果表明,Pd/TiO2薄膜的光催化能力显著地提高,在紫外光、可见光作用下的光催化效率分别提高了2.25倍和3.4倍.     

355nmZrO2凝胶色分离光栅的设计和衍射效率测量

基于光敏凝胶法二元光学元件制作工艺,设计制作了ZrO₂介质色分离光栅。使用白光干涉仪和椭圆偏振光谱仪分别测试了光栅的几何结构参数和折射率;编制程序计算了光栅的理论衍射效率;搭建光路实测了光栅在设计波长的分频效果,并与理论值进行了对比分析。结果显示,对波长为355nm的激光,光栅的零级效率接近70%,而对1064nm和532nm的激光,其残留约13%,理论计算值与实测结果符合较好。     

用掠入射XAFS方法研究Ti/Ni/Ti纳米薄膜的界面结构

在上海光源BL14W1线站建立了掠入射XAFS(GI-XAFS)方法,利用GI-XAFS方法并结合X射线反射(XRR)研究了直流磁控溅射方法生长在W/Si基底上的Ti/Ni/Ti纳米薄膜的界面结构随Ni层厚度的变化.结果表明,随着薄膜厚度的增加,Ni/Ti界面层间的相互扩散有所增加,Ni层厚度为5 nm时,Ni/Ti界...     

掺钛对UO2微球晶粒生长机制的影响

采用溶胶-凝胶方法制备掺钛0.3%(质量分数,下同)UO2微球,用金相显微镜观察微球微观结构、图像分析仪计算微球晶粒尺寸。对掺钛0.3%UO2微球晶粒长大机制进行了研究。经过计算得到在1 250～1 550℃之间掺钛UO2微球晶粒生长的平均活化能Ea=232.79kJ/mol,明显地低于UO2微球晶粒生长的平均活化能(Ea0=518.32kJ/mol);掺钛UO2微球在烧结后期(1 250℃之后),微球部分区域可能形成高价态的U4O9相,加快了U原子扩散速度,加速了晶粒生长。     

Characterization of Tantalum Oxide Thin Films Prepared by Cylindrical Magnetron Sputtering: Influence of O2% in the Gas Mixture

The amorphous tantalum oxide thin films were prepared by DC reactive magnetron cylindrical sputtering onto p-type silicon (100) substrate. We report the composition and optical properties of thin films under O₂ amount variation. The sample’s reflectance was measured with a UV-Vis-NIR spectrophotometer (320–850?nm). The optical characterization of thin layers was analyzed by ellipsometry in spectral region for wavelength from 250 to 850?nm to obtain the refractive index and film’s thickness. The RMS roughness and grain size were investigated by atomic force microscope (AFM). Simulations to Rutherford backscattering spectroscopy (RBS) data revealed film’s stoichiometry. The reflectance, refractive index, thickness, RMS roughness and grain size were found to be affected by increasing oxygen amount. We calculated the porosity of grown layers using measured refractive index at the wavelength of 633?nm.     

Annealing Temperature dependence of Photoluminescence from Silicon-rich silica Films

1. IlltroductionSince the observation of strong photolumines-cence (PL) of porous silicon [1], a great interest innanocrystalline silicon (nc-Si) has been stimulatedbecause of its potential applications as light-emittingdevices comPatible wlth silicon--based optoelectronicintegrated circults. In recent years, many techniques[2~5], such as sputterlng, laser chemlcal vaPor de-position, Ion implanatation, and plasma enhancedCVD ! have been adopted for preparatlon of nc-Sl em-bedded in the mat…     

Development of Wide Band Neutron Monochromator Consisting of a Stack of Multilayers

A wide band neutron monochromator consisting of a stack of four multilayers on two Si wafers has been developed. One multilayer has 201 Ni/Ti layers. The layer thickness is gradually changed in order to extend the neutron reflection wavelength range similar to a supermirror. Multilayers were fabricated by the vacuum evaporation methods on each side of a Si substrate of 225 μm in thickness. Neutron reflectivity was measured by the θ-2θ reflectometer using cold neutrons. The neutron reflection wavelength was broadened to 19–40 nm by this stack from 26–40 nm of one multilayer.     

Transmission electron microscopy of αZrO2 films formed in 573 K oxygen

Oxide films between 10 and 362 nm thickness were removed from zirconium substrates and examined by selected area electron diffraction and transmission electron microscopy. Evidence was found for a dynamic process of oxide crystallite nucleation, recrystallization and growth. Investigations were limited to oxide film thicknesses of less than 365 nm due to the presence of a dense network of amorphous oxide protusions at the oxide/metal interface.     

Depth profiling of Al2O3 + TiO2 nanolaminates by means of a time-of-flight energy spectrometer

Atomic layer deposition (ALD) is currently a widespread method to grow conformal thin films with a sub-nm thickness control. By using ALD for nanolaminate oxides, it is possible to fine tune the electrical, optical and mechanical properties of thin films. In this study the elemental depth profiles and surface roughnesses were determined for Al₂O₃ + TiO₂ nanolaminates with nominal single-layer thicknesses of 1, 2, 5, 10 and 20 nm and total thickness between 40 nm and 60 nm. The depth profiles were measured by means of a time-of-flight elastic recoil detection analysis (ToF-ERDA) spectrometer recently installed at the University of Jyväskylä. In TOF-E measurements ⁶³Cu, ³⁵Cl, ¹²C and ⁴He ions with energies ranging from 0.5 to 10 MeV, were used and depth profiles of the whole nanolaminate film could be analyzed down to 5 nm individual layer thickness.     

CEMS AND COUPLING EFFECT OF INTERLAYERS IN MULTILAYERED FeSi/Si AMORPHOUS FILMS

Multilayered FeSi/Si amorphous films with fixed FeSi layer thickness and different Si layer thicknesses have been studied by conversion electron Mossbauer spectroscopy at room temperature. The results showed that with decreasing the Si layer thickness, the hyperfine field of samples increased and the thickness of interface dead layers arisen from the atomic interdiffusion effect decreased. These are due to the coupling effect between the magnetic layers. When the Si layers are thinner than 0.88 nm, the direction of the magnetization is out of the film plane.     

PIXE measurements of Kr-sputtered TiN coatings

Titanium nitride films of 30–300 nm thickness deposited via dc magnetron sputtering were irradiated with 150–700 keV Kr ions at fluences up to 2.1 × 10¹⁷ cm⁻². These films were then scanned with a well-collimated 400 keV proton beam and the X-ray yield of Ti was measured both in and outside the Kr beam spot. This procedure results in a precision determination of the average film thickness (± 1% in the case of tens of nm films). The PIXE results are found to be consistent with RBS data of the same specimens. Sputtering yields were determined from the variation of X-ray yields assuming unchanged Ti/N stoichiometry in the implanted area. For thick TiN films (d₀ > 100 nm) the sputtering yields are in good agreement with predictions of the collisional cascade model by Sigmund. In contrast, sputtering of thin layers (d₀ = 30 nm) depended sensitively on the ion energy, being a factor of 2 higher at 150 keV than at 500 keV.     

Changes to the reflectance of Be mirrors due to deuterium plasmas contaminated with oxygen

The reflectance of Be mirrors due to impact by ions from a deuterium plasma has been studied under several bombardment conditions. Analysis of the resulting surface films has been performed using various diagnostic techniques, with the conclusion that the primary factor leading to the decrease in reflectance following bombardment with energetic ions is the conversion of the surface oxide layer, composed of BeO, to the hydroxide, Be(OD)₂, with a corresponding increase in the optical extinction coefficient. The increase in the thickness of the layer is also important. Modifications to the surface layer are thought to involve a balance between the ion-induced diffusion of Be atoms to the surface where they may react with incident D and O atoms, and physical and chemical sputtering processes. For incident ion energies less than ∼50 eV, chemical reactions leading to disoxidation of the oxide-hydroxide film dominate, while keV-range ions (primarily D, but with some O impurities) lead to the formation of hydroxide, and an increase in the surface layer thickness.     

Investigation of conductive and transparent ITO/Ni/ITO multilayer films deposited by a magnetron sputter process

Transparent conducting ITO/Ni/ITO films were deposited by RF magnetron sputtering of Sn-doped In₂O₃ and DC magnetron sputtering of Ni on unheated polycarbonate substrates. Ni interlayers with thicknesses of 5, 10, and 20 nm were used as intermediate metallic layers.Changes in the work function and optical, electrical and structural properties of the films were examined with respect to Ni layer thickness. The work function was measured to be about 4.5 eV and was found to be independent of Ni layer thickness. However, the structural, optical, and electrical properties of the films were influenced by the Ni thickness. As-deposited ITO single layer films showed In₂O₃ diffraction peaks for the (2 2 2) and (4 0 0) planes, while after insertion of the Ni layer between ITO films, these diffraction peaks disappeared. The electrical resistivity decreased with the Ni intermediated film and the optical transmittance also decreased due to increased optical absorption. The figure of merit reached a maximum of 2.0 × 10⁻³ Ω⁻¹ for a 5 nm-thick inserted Ni film, which is greater than the value for as-deposited ITO films.     

同步辐射软X光Al衰减膜透射率的测量

分参数测量Ａｌ衰减膜的质量厚度和氧化层后，通过计算到了Ａｌ膜的透过率。为检验计算结果的正确性，在北京同步辐射软Ｘ光反射率装置上进行Ａｌ衰减膜透过率的直接测量。二者的结果在最大偏差１１％范围内符合。