铀表面等离子体浸没离子注入沉积制备氮化层+Ti/TiN多层膜的结构与性能

为了改善金属铀的摩擦磨损和抗腐蚀性能,采用等离子体浸没离子注入沉积(PIII&D)技术在铀表面氮化,再沉积Ti/TiN多层膜.利用扫描电镜和X射线衍射分析了薄膜的形貌和组织结构;对薄膜的摩擦磨损和抗湿热腐蚀性能进行了测试.结果表明:薄膜表面致密,界面晶粒柱状生长方式被阻断,晶粒细化;薄膜为Ti和TiN的双相结构,衍射谱中出现了UO_2和U_2N_3的衍射峰;薄膜大大提高了铀基体的摩擦磨损和抗湿热腐蚀性能,调制周期对薄膜性能的影响较大.     

医用金属表面溶胶-凝胶法和离子束合成TiO2薄膜的结构、性能比较

采用溶胶-凝胶法和离子束增强沉积法在医用NiTi合金表面制备TiO2薄膜以提高其生物相容性.利用X射线衍射(XRD)、原子力显微镜(AFM)和X光电子能谱(XPS)对薄膜的结构、表面形貌及组成进行了比较研究;电化学腐蚀实验表明,两种方法制备的TiO2薄膜对金属基体均起到一种保护膜的作用,能够提高医用金属材料在模拟体液中的抗腐蚀性;对薄膜表面固定肝素抗凝血分子进行研究发现,溶胶-凝胶法制备的TiO2薄膜表面能够获得较好的肝素固定效果.     

脉冲激光沉积Bi0.5(Na0.7K0.1Li0.2)0.5TiO3无铅压电薄膜的研究

采用脉冲激光沉积制备了新型无铅压电Bi0.5(Na0.7K0.1Li0.2)0.5TiO3陶瓷薄膜,分别利用X射线衍射仪、X射线光电子谱、俄歇电子能谱、原子力显微镜及扫描电镜研究了该薄膜的晶体结构、组成成分及表面形貌.结果表明,薄膜基体温度和工作气压对所生长的薄膜影响较大;在SiO2/Si基片上制备Bi0.5(Na0.7K0.1Li0.2)0.5TiO3薄膜的最佳温度和氧气压力分别为600℃和13Pa;利用脉冲激光沉积的薄膜具有精细的表面结构.     

微等离子体氧化法TiO2、TiO2(W)薄膜的制备及性能

利用微等离子体氧化方法,在纯Ti金属表面制备TiO2、TiO2(W)薄膜,并用X射线衍射(XRD)、扫描电镜(SEM)初步研究了薄膜的组织结构和表面形貌.在不同的条件下,得到3种不同类型结构组成的薄膜:单一TiO2的锐钛型结构、单一TiO2金红石结构及TiO2(W)薄膜;同时对薄膜的催化特性进行了初步的研究.     

微等离子体氧化法TiO2、TiO2(W)薄膜的制备及性能

利用微等离子体氧化方法,在纯Ti金属表面制备TiO2、TiO2(W)薄膜,并用X射线衍射(XRD)、扫描电镜(SEM)初步研究了薄膜的组织结构和表面形貌.在不同的条件下,得到3种不同类型结构组成的薄膜单一TiO2的锐钛型结构、单一TiO2金红石结构及TiO2(W)薄膜;同时对薄膜的催化特性进行了初步的研究.     

磁控溅射制备TiO2薄膜对医用NiTi合金弹簧圈的表面改性

采用非平衡磁控溅射法制备了3种TiO2薄膜,对医用NiTi合金弹簧圈进行了表面改性处理.运用X射线衍射(XRD)、X射线光电子能谱仪(XPS)、原子力显微镜(AFM)﹑扫描电子显微镜(SEM)等手段系统研究了薄膜的表面结构、成分、微观形貌等,同时对薄膜的接触角进行了测试.通过血小板粘附和人脐静脉内皮细胞种植试验研究和评价了薄膜的血栓形成能力和内皮化性能.结果表明,医用NiTi合金弹簧圈表面镀一定结构和性质的TiO2薄膜后,其血栓形成能力和内皮化性能得到明显提高.     

Ti6Al4V磁控溅射沉积Ti-Ag-(N)薄膜及其抗菌性的研究

利用磁控溅射法在医用钛合金Ti6Al4V表面制备Ti-Ag、Ti-Ag-N薄膜。采用扫描电子显微镜、X射线衍射、X射线能量色散谱、X射线光电子能谱分析薄膜的表面形貌、微观结构、化学成分和化学价态。采用平板计数法测试薄膜对大肠杆菌的抗菌性。研究结果表明:薄膜主要由Ti、Ag、(N)组成,且Ag是以Ag~0形式存在;与基材相比,两种薄膜对大肠杆菌(E.coli)均有抗菌性,且Ti-Ag-N薄膜表现出更优越的抗菌性能。     

磁控溅射法制备的纳米金薄膜的工艺条件和结构分析

通过直流溅射沉积法在玻璃衬底上制备了不同生长条件下的纳米金薄膜,利用X射线衍射(XRD)和原子力显微镜(AFM)对其进行表面形貌分析.XRD 图显示Au膜具有(111)面择优取向;AFM图显示,在不同的生长阶段Au膜具有不同的表面微结构.总结了不同的工艺条件对薄膜晶粒生长的影响,这项研究对实现金属薄膜的可控性生长有重要意义.     

氧化钛薄膜表面羟基活化能力及对生物相容性的影响

采用非平衡磁控溅射法制备了3种不同结构的TiO2薄膜,对所得TiO2薄膜运用碱处理方法进行表面处理,期望在材料表面获得羟基活性基团.运用X射线衍射(XRD)研究了薄膜的表面结构.利用傅里叶红外技术(FTIR)和X射线光电子能谱仪(XPS)等手段对活化处理前后样品表面的羟基基团进行检测,并对活化前后样品进行了内皮细胞培养和血小板黏附实验.结果表明,运用碱处理方法,可以在锐钛矿型以及金红石与锐钛矿的混晶结构TiO2薄膜表面形成活性羟基基团;相比于金红石型TiO2薄膜,混晶结构和锐钛矿型具有较好的羟基活化能力.生物相容性实验表明,碱活化处理后样品表面细胞生长数目多于活化前样品,血小板黏附数量少于活化前样品,表面活性基团的存在有利于提高TiO2薄膜材料的生物相容性.此外,影响TiO2薄膜表面生物活化性能的因素进行了初步探讨.     

利用铜基底增强化学镀法制备金纳米颗粒/石墨烯复合薄膜

采用电泳沉积技术在铜基底表面制备了石墨烯(GNS)薄膜,进而利用氯金酸水溶液与铜基底之间的电置换反应在GNS薄膜表面沉积金纳米颗粒,从而得到金纳米颗粒/石墨烯(Au/GNS)复合薄膜.通过原子力显微镜(AFM),场发射扫描电镜(FE-SEM)X射线衍射(XRD)等测试手段对样品进行厚度,微观结构和化学成分分析,研究了不同置换反应时间对所得复合薄膜形貌和结构的影响,并分析了复合薄膜的沉积机理.     

Uranium and thorium sequestration by a Pseudomonas sp.: mechanism and chemical characterization

The mechanism and chemical nature of uranium and thorium sequestration by a Pseudomonas strain was investigated by transmission electron microscopy, energy dispersive X-ray (EDX) analysis, FTIR spectroscopy and X-ray diffractometry. Atomic force microscopy (AFM) used in the tapping mode elucidated the morphological changes in bacterial cells following uranium and thorium binding. Transmission electron microscopy revealed intracellular sequestration of uranium and thorium throughout the cell cytoplasm with electron dense microprecipitations of accumulated metals. Energy dispersive X-ray analysis confirmed the cellular deposition of uranium and thorium. EDX and elemental analysis of sorption solution indicated the binding of uranium and thorium by the bacterial biomass via displacement of cellular potassium and calcium. The strong involvement of cellular phosphate, carboxyl and amide groups in radionuclide binding was ascertained by FTIR spectroscopy. X-ray powder diffraction (XRD) analyses confirmed cellular sequestration of crystalline uranium and thorium phosphates. Overall results indicate that a combined ion-exchange-complexation-microprecipitation mechanism could be involved in uranium and thorium sequestration by this bacterium. Atomic force microscopy and topography analysis revealed an undamaged cell surface with an increase in cell length, width and height following radionuclide accumulation. The arithmetic average roughness (R(a)) and root mean square (RMS) roughness (R(q)) values indicated an increase in surface roughness following uranium and thorium sequestration.     

ZnS薄膜的溅射沉积及其XPS研究

用Ａｒ＾＋束溅射沉积技术在ＨｇＣｄＴｅ表面实现了ＺｎＳ的低温沉积,用Ｘ射线光电子能谱（ＸＰＳ）对上述ＺｎＳ薄膜能主热蒸发ＺｎＳ薄膜中的Ｚｎ、Ｓ元素的化学环境进行了对比实验研究,实验表明：离子束溅射沉积ＺｎＳ薄膜具有很好的组份均匀性,未探测到元素Ｚｎ、Ｓ的沉积。     

铀表面脉冲辉光等离子氮化初步研究

采用脉冲辉光等离子体离子氮化技术对贫铀表面进行了氮化处理,采用俄歇电子能谱(AES)对氮化层进行元素深度剖析,采用X射线衍射(XRD)、扫描电子显微镜(SEM)对氮化层组织结构进行了分析表征。结果表明:脉冲偏压-900 V,工作氮分压50 Pa、100 Pa,氮化时间2.5 h~4 h下在贫铀表面能获得约20μm厚的氮化层,氮化层为U2N3的单一立方结构且均匀致密,脉冲辉光等离子氮化技术能在贫铀表面实现氮化。     

不同有机单体等离子体聚合的对比研究

采用等离子体聚合的方法对正丙醇和丙烯醇进行了聚合,成功地在Si基体上得到了有机高分子薄膜,利用FT-IR,XPS研究了薄膜的结构,表明薄膜呈现出一种嵌段的高分子薄膜结构,利用AFM研究了薄膜的表面形貌并且测量了表面粗糙度,研究表明,等离子体聚合后薄膜表面十分平整,平均粗糙度在2 nm以内,利用测量薄膜表面接触角的方法计算了材料的表面能以及临界表面自由能,并且进行了讨论分析.     

磁控反应溅射MoS2/Ti/C复合薄膜的组织结构及摩擦磨损性能

为了提高MoS2薄膜在室温潮湿大气条件下的摩擦磨损性能,通过磁控反应溅射制备了MoS2/Ti/C复合薄膜.采用能谱仪(EDS)、X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)对薄膜的成分、相组成和形貌进行表征,采用纳米压痕仪测试薄膜的结合力、纳米压痕硬度,采用多功能微摩擦磨损试验机测试薄膜的摩擦系数,并采用...     

氮流量对贫铀表面磁控溅射CrN_x薄膜结构与性能的影响

金属铀的化学性质十分活泼,极易发生氧化腐蚀.为改善基体的抗腐蚀性能,采用非平衡磁控溅射技术在金属铀表面制备了不同氮含量的CrNx薄膜.采用扫描电子显微镜(SEM)、X射线衍射技术(XRD)、X射线光电子能谱(XPS)、动电位极化曲线,分别研究了薄膜形貌、物相结构、表面元素化学价态及抗腐蚀性能.结果表明,当氮流量为10 sccm时薄膜主要为体心立方的α-Cr,随氮流量的增大,薄膜转化为六方Cr2N和立方CrN结构,其择优取向由Cr(110)转化为Cr2N(111)及CrN(200),金属态Cr的含量逐渐减少,氮化态Cr的含量增多,Cr2p3/2的结合能峰位逐渐向高结合能方向移动.CrNx薄膜呈纤维状结构,当氮流量增大到30 sccm时,生成了Cr2N的密排结构,有效改善了薄膜的致密性.在金属铀表面制备CrNx薄膜后,自然腐蚀电位增大,腐蚀电流密度降低,当氮流量增大到30 sccm时,薄膜的自然腐蚀电位提高了近550 mV左右,腐蚀电流密度降低约两个数量级,有效改善了贫铀表面的抗腐蚀性能.     

Polarity conversion of hydride vapor phase epitaxy growing GaN via growth interruption modulation

GaN films were deposited by hydride vapor phase epitaxy with and without adopting growth interruption modulation (GIM). The surface morphologies of these samples were observed by atomic force microscopy. After chemical etching, the surface morphology of GaN film grown directly on sapphire changed greatly and turned out to be N-polarity, which could be changed into Ga-polarity when growing via interruption modulation. Photoluminescence spectra showed that optical property of Ga-polar film was better than that of N-polar film. High resolution X-ray diffraction revealed the high crystalline quality GaN film grown by using the GIM method. The polarity conversion was the result of surface reconstruction when adopting GIM method.     

A novel technique for processing functionally graded HA coatings

Hydroxyapatite (HA) films were deposited using dual ion beam sputtering. Deposition was carried out with an in situ heat treatment at three temperature settings during deposition. X-ray diffraction of the films at the surface revealed that the deposited film is composed of hydroxyapatite crystalline and amorphous phases. Cross-sectional transmission electron microscopy analysis displayed that the films have a graded crystal structure with the crystalline layer near the substrate and the amorphous layer at the top surface. Compositional analysis was performed using SEM-EDX at the top surface as well as STEM-EDX at the cross-section of the film. The average calcium to phosphorous ratio at the surface is 1.46, obtained by SEM-EDX. The Ca/P ratios in the crystalline and amorphous layers of the film are 1.6 to 1.7, close to the ratio of 1.67 for HA.     

一种TiAlN多层膜制备新方法

采用自行设计制造的离子束联合溅射系统,将磁控溅射与离子注入技术相结合,在镁合金表面形成多层TiAlN强化膜.用金相显微镜、X射线衍射仪、原子力显微镜、摩擦磨损仪等手段,研究了多层膜的表面形貌、结构和性能.结果表明,TiAlN膜膜表面光滑致密、孔隙率大大降低,粗糙度为42.28nm,由TiAlN强化相组成;成膜后耐磨性有所提高,但摩擦系数变化不大,未达到减摩作用.     

Development of an enrichment measurement technique and its application to enrichment verification of gaseous UF6

A technique has been developed to verify the enrichment of gaseous UF₆ inside cylinders. This technique combines an X-ray fluorescent measurement of the total amount of gaseous uranium with a measure of the 185.7 keV gamma ray from ²³⁵U using two collimators to obtain an enrichment that is independent of the pressure of the gaseous uranium and independent of the deposit that forms on a surface in contact with UF₆. This technique has the required sensitivity to determine whether the process gas is of uranium enrichment ≤ 20% or >20%.