快重离子辐照金红石型TiO2的肿胀效应及化学蚀刻行为研究

二氧化钛（Titatium Dioxide,简称TiO₂）晶体在中能重离子辐照时表面会出现肿胀效应, 肿胀高度与入射离子的电子能损和辐照注量有关。 辐照后的TiO₂在一定条件下能够被氢氟酸溶液化学蚀刻,化学蚀刻的电子能损阈值为8.2keV/nm,未辐照TiO₂呈现几乎零蚀刻率。要达到饱和蚀刻深度,辐照离子的注量必须大于或等于1×1013ions/cm2。采用离子辐照的潜径迹理论分析研究了辐照损伤及对化学蚀刻的影响, 快重离子辐照结合化学蚀刻是制备TiO₂微结构的有效方法。 There appears volume swelling on the surface of the irradiated rutile TiO₂ crystal and the volume swelling is affected by the ion fluence and the electronic stopping power. To induce adequate irradiation damage for the chemical etching, the irradiation parameters must fulfill some requirement. There is minimum electronic stopping power for the chemical etching of the irradiated region in TiO₂ crystal, which is about 8. 2 keV/nm. If the ion fluence is below 1×1013ions/cm2, the saturated etching depth of the irradiated region in TiO₂crystal cannot be reached. The irradiation damage based on latent track formation frame and the theoretical linkage to the etching technique is investigated. It is hopeful to fabricate micro and nano scale structurce in rutile TiO₂ crystal by using the ion irradiation and chemical etching technique.      

22 MeV/u的Fe离子在PET 膜中引起的辐照效应研究

用能量为22 MeV/u的 Fe离子在室温和真空条件下辐照了多层堆叠的半晶质聚酯膜, 采用傅里叶转换红外吸收光谱、 紫外/可见吸收光谱 和X射线衍射技术分析测量了辐照后聚酯膜的微观结构所发生的变化, 详细研究了分子结构的变化和非晶化转变与离子剂量、 离子在样品中的平均电子能损以及吸收剂量的依赖关系． 分析结果表明: 辐照导致化学键的断裂、 新化学键的形成和非晶化转变． 非晶化效应和化学键的断裂随离子剂量和电子能损的增加而增大, 但变化的总量仅依赖于总的吸收剂量, 表明在所涉及的能损范围里, 辐照产生的变化与辐照离子的种类和能量没有直接的关系, 而只决定于材料对辐照离子能量的吸收程度． Semicrystalline polyethylene terephthalate (PET) film stacks were irradiated with 22 MeV/u Fe ions at room temperature under vacuum. Ion beam induced microscopic structural modifications and amorphous transformation were investigated by means of Fourier transform infrared spectrosocopy (FTIR), ultraviolet visible absorption spectrosocopy (UV/Vis) and X ray diffractometer (XRD). It was found that irradiation induces bond breaking, formation of new free radiculs and amorphous transformation. These effects were found to depend on ion fluence , the electronic energy loss and aborbed dose. The creation of alkyne groups was found only at the aborbed dose higher than 5.0 MGy.     

快重离子辐照引起Ni/SiO2界面原子混合及相变研究

在室温下用308 MeV的Xe离子和853 MeV的Pb离子辐照Ni/SiO2样品, 用卢瑟福背散射和X射线衍射技术对样品进行了分析。 通过分析Ni/SiO2样品中元素成分分布和结构随离子辐照剂量和电子能损的变化, 探索了离子辐照在Ni/SiO2样品中引起的界面原子混合与结构相变现象。 实验结果显示, Xe和Pb离子辐照均能引起明显的Ni原子向SiO2基体的扩散并导致界面附近Ni, Si和O原子的混合。 实验观测到低剂量Xe离子辐照可产生NiSi2相, 而高剂量Xe离子辐照则导致了Ni3Si和NiO相的形成。 根据热峰模型, Ni原子的扩散和新相的形成可能由沿离子入射路径强电子激发引起的瞬间热峰过程驱动。Ni/SiO2 interface were irradiated at room temperature with 308 MeV Xe ions to 1×1012, 5×1012 Xe/cm2 and 853 MeV Pb ions to 5×1011 Pb/cm2, respectively. These samples were analyzed using Rutherford Backscattering Spectrometry (RBS) and X ray diffraction spectroscopy (XRD), from which the intermixing and phase change were investigated. The obtained results show that both Xe and Pb ions could induce diffusion of Ni atoms to SiO2 substrates and result in intermixing of Ni with SiO2. Furthermore, 1.0×1012 Xe/cm2 irradiation induced the formation of NiSi2 and 5.0×1012 Xe/cm2 irradiation created Ni3Si and NiO phases. The diffusion of Ni atoms and the formation of new phase may be driven by a transient thermal spike process induced by the intense electronic energy loss along the incident ion path.     

HIRFL辐照终端照射野均匀度与离子通量的关系

采用固体核径迹探测器聚碳酸脂膜,测定了兰州重离子研究装置提供的55MeV/u40Ar和80MeV/u20Ne离子束经辐照终端束流均匀化扫描装置后照射野均匀度与离子通量之间的关系.结果表明:对于40Ar和20Ne离子束,离子通量小于1×106和2×107ions/cm2时,横向照射野均匀度缓Ne离子束照射慢增加;当离子通量分别介于1×106—1×107和2×107—1×108ions/cm2时,40Ar和20野均匀度逐渐增加;离子通量达到1×107和1×108ions/cm2时,40Ar和20Ne离子束照射野均匀度分别约为58%和61%.从而说明,辐照终端束流扫描装置对束流的均匀化程度目前并不能满足辐照生物效应、辐射育种和重离子治癌等研究工作的需要,须对其性能做进一步的提高. Using 55 MeV/u 40Ar and 80 MeV/u20Ne ion beams delivered by the Heavy Ion Research Facility at Lanzhou (HIRFL), the relationships between the irradiation homogeneities in irradiation fields generated by the beam scanning device located at the irradiation terminal of the HIRFL and ion fluence were measured respectively with 100 μm polycarbonate films by means of nuclear track detection. The results show that the homogeneity increases when the ion fluence are lower than ........     

MeV能量的重离子辐照GaN的HRXRD研究

分别进行了2.3 MeV20 Ne8+ 离子和5.0 MeV84 Kr19+ 离子辐照GaN样品的实验, 并对实验样品进行了HRXRD的分析。结果发现, 随着这两种离子辐照剂量的增大, GaN的HRXRD谱（0002）衍射峰的峰位出现了向小角侧有规律的移动, 并在较高剂量时衍射峰发生分裂。同时, 对衍射峰的峰位的移动和峰形的变化等现象反映的辐照损伤机制进行了研究, 并探讨了电子能损与核能损各自在晶格损伤中的作用。Irradiation experiments of gallium nitride (GaN) with 2.3 MeV20 Ne8+ and 5.0 MeV84 Kr19+ respectively were performed. The irradiated samples were analyzed using the high\|resolution X\|ray diffraction (HRXRD) spectrometry. It was found that the diffraction peak of GaN (0001) exhibited regular shift to smaller diffraction angles with the increase of ion fluence for the both ions, and the diffraction peak split into a few sub\|peaks at higher irradiation dose. Underlying mechanisms of the observed peak shift and split were investigated, the contributions of different energy losses to the damage accumulation in the irradiated GaN were discussed.     

荷能离子在C60薄膜中引起的辐照效应

用 Raman散射和 XPS技术分析了能量为几百 ke V到几百 Me V的多种离子在 C60 薄膜中引起的辐照效应.分析结果表明 ,在低能重离子辐照的 C60 薄膜中 ,其晶态向非晶态的转变过程是由核碰撞主导的.在快离子 (1 2 0 ke V的 H离子和171.2 Me V的 S离子 )辐照的情况下,电子能损起主导作用.发现在H离子辐照过程中,电子能损有明显的退火效应 ,致使 C60 由晶态向非晶态转变的过程中,经历了一个石墨化的中间过程;而在 S离子辐照的情况下 ,电子能损的破坏作用超过了退火效应 ,因此 ,在C₆₀ 由晶态向非晶态转变的过程中,无石墨化的中间过程.Irradiation effecs (mainly including transformation from crystalline into amorphous state) of C 60 films induced by 120 keV H, He, N, Ar, Fe and Mo ions, 240 keV and 360 keV Ar ions, and 171.2 MeV, 125.3 MeV and 75.8 MeV S ions were analysed by means of Raman scattering and XPS technique. The analysis results indicate that amorphization process in the cases of N, Ar, Fe and Mo ions irradiation is dominated by nuclear collision, but in the case of H ion irradiation, the process is...     

Ne离子束辐照引起Gd2Ti2O7烧绿石体积肿胀效应研究

在液氮低温下用400 keV的Ne2+离子束对Gd₂Ti₂O₇多晶烧绿石进行了辐照实验研究, 离子束辐照量范围为5×1014—1×1016ions/cm2。利用掠X射线衍射技术对样品辐照层的结构变化进行了分析表征, X射线的掠射角分别为γ=0.25°, 0.5°, 1°和3°。结果表明: 在该实验条件的离子束辐照下, Gd₂Ti₂O₇辐照层会发生明显的体积肿胀效应, 体积肿胀程度随入射离子束辐照量的增大而增大; 在同一辐照量下, 辐照层的体积肿胀程度也随X射线入射角的增大而增大。当辐照量达到1×1016ions/cm2时, 辐照层发生非晶化相变。Polycrystalline pyrochlore Gd₂Ti₂O₇ compounds were irradiated with 400 keV Ne2+ ions at cryogenic temperature (~77 K). The irradiation fluences was ranging from 5×1014 to 1×1016 ions/cm2, corresponding to a peak ballistic damage dose of ~0.16 to 3.3 displacements per atom . Irradiation\|induced structural evolution was examined using grazing incidence X\|ray diffraction (GIXRD) at angles from 0.25° to 3° degrees. It was found that the lattice parameter increases as a function of (1) X\|ray incident angle and (2) ion irradiation fluence, suggesting that the irradiated layer is volumetrically swelled compared with the underlying un\|irradiated substrate. At ion fluence of 1×1016 ions/cm2, the irradiation layer was found to be amorphous.     

高能Xe离子辐照引起的注碳a:SiO2中新结构的形成

先用120keV的碳离子注入非晶二氧化硅a:SiO2薄膜，再用能量为1754MeV的Xe离子辐照。注碳量为5．0×10^16—8．6×10^17ion／cm^2，Xe离子辐照剂量为1．0×10^11和5．0×10^11ion／cm^2。辐照后的样品中形成的新结构用显微傅立叶变换红外光谱仪进行测试分析。结果表明，Xe离子辐照引起了注碳a:SiO2中Si—C，C—C，Si—O—C键以及CO和CO2分子的形成与演化。在注碳量较高时，Xe离子辐照在样品中产生了大量的Si—C键。与注入未辐照和辐照的低注碳量样品比较，增强的Si—C键的形成，预示着辐照可引起注碳a:SiO2样品中的SiC结构相变。Amorphous silicon-dioxide （a:SiO2） films were firstly implanted at room temperature （RT） with 120 keV C-ions to doses ranging from 5.0 × 10^16 to 8.6 × 10^17 ion/cm^2, and then the C-doped a:SiO2 films were irradiated at RT with 1 754 MeV Xe ions to 1.0 × 10^11 and 5.0 × 10^11 ion/cm^2, respectively. The information of new tex- ture formation in the C-doped SiO2 films after high-energy Xe ion irradiation was investigated using micro-FTIR measurements. The obtained results showed that Si--C, C--C, Si--O--C bonds as well as CO and CO2 molecules were formed in the C-doped a-SiO2 films after Xe ion irradiation. Furthermore, Xe-ion irradiation induced a plenteous formation of Si--C bonds in the high dose C-ion implanted a:SiO2 films. Compared with the C-implanted sampies without Xe-ion irradiation and the low dose C-implanted samples with Xe-ion irraddiation, the enhanced and plenty of Si--C bond formation implied that the phase of SiC structures may be produced by Xe-ion irradiation in the high dose C-ion implanted a:SiO2 films.     

Fe/Nb多层膜中离子辐照效应研究(英文)

〗采用磁控溅射技术在Si衬底上沉积Si/\[Fe(10 nm)/Nb(4 nm)/Fe(4 nm)/Nb(4 nm)\]2/ \[Fe(4 nm)/Nb(4 nm)\]4多层膜。 用2 MeV的 Xe离子在室温下辐照多层膜。采用俄歇深度剖析、X射线衍射和振动样品磁强计分析辐照引起的多层膜元素分布、 结构及磁性变化。AES深度剖析谱显示当辐照注量达到1.0×1014 ions/cm2时, 多层膜界面两侧元素开始混合; 当辐照注量达到2.0×1016ions/cm2时, 多层膜层状结构消失, Fe层与Nb层几乎完全混合。XRD谱显示, 当辐照注量达到1.0×1014ions/cm2时, Nb的衍射峰和Fe的各衍射峰的峰位相对于标准卡片向小角方向偏移, 这说明辐照引起Nb基和Fe基FeNb固溶体相的形成;当辐照注量大于1.0×1015 ions/cm2时, 辐照引起非晶相的出现。 VSM测试显示,多层膜的磁性随着结构的变化而变化。 在此实验基础上, 对离子辐照引起界面混合现象的机理进行了探讨。The behavior of the metallic multilayers of Si/\[Fe(10 nm)/Nb(4 nm)/Fe(4 nm)/ Nb(4 nm)\]2/\[Fe(4 nm)/Nb(4 nm)\]4 under 2 MeV Xe ion irradiation has been investigated by depth profile analysis of Auger electron spectroscopy,X ray diffraction and vibrating sample magnetometer. The obtained experimental results show that the inter mixing between Fe and Nb layers occurs in the 1.0×1014 ions/cm2 irradiated multilayer sample which results in the formation of Nb based and Fe based FeNb solid solution. For the samples irradiated to fluence larger than 1.0×1014 ions/cm2, amorphisation is observed, and moreover, the layered structure of the multilayer samples is broken up completely for the samples under 1.0×1016 or 2.0×1016 ions/cm2 irradiation. Vibrating sample magnetometer measurement also reveals that the magnetization of the samples changes with the evolution of the structure of multilayers. Possible mechanism of the modification in Fe/Nb multilayers induced by Xe ion irradiation is briefly discussed.     

Kr L X-ray and Au M X-ray emission for 1.5 MeV–3.9 MeV Kr~(13+) ions impacting on an Au target

Kr L X-ray and Au M X-ray emission for Kr13＋ ions with energies of 1.5 MeV and 3.9 MeV impacting on an Au target are investigated at heavy ion research facility in Lanzhou （HIRFL）. The L-shell X-ray yield per ion of Kr is measured as a function of incident energy. In addition, Kr L X-ray production cross section is extracted from the yield and compared with the result obtained from the classical binary-encounter approximation （BEA） model. Furthermore, the intensity ratio of the Au M/33 to Ma1 X-ray is investigated as a function of incident energy.     

快重离子辐照聚酰亚胺潜径迹的电子能损效应

快重离子辐照聚合物材料时，由于密集电离激发在其路径上产生几纳米直径的潜径迹，径迹形貌受离子种类、离子能量等多种因素的影响.为了研究电子能损对径迹形成所起的作用，利用1.158GeV 的Fe⁵⁶离子和 1.755GeV Xe¹³⁶离子在室温真空环境下辐照叠层聚酰亚胺(PI)薄膜，结合傅里叶转换红外光谱(FTIR)分析技术对辐照引起的化学变化进行了测量.聚酰亚胺官能团的降解及炔基的生成是离子辐照聚合物的主要特征，在注量1×10¹¹到6×10¹²/cm²范围及较宽的电子能损(dE/dX)_e范围 (Fe⁵⁶ 离子：2.2 到 5.2 keV/nm， Xe¹³⁶ 离子：8.6 到 11.3 keV/nm)对官能团的断键率及炔基生成率进行了研究. 红外结果显示在实验涉及的能损范围都有炔基生成，应用径迹饱和模型对实验结果进行拟合，不同能损下的平均损伤径迹半径及炔基生成径迹半径被得到，通过热峰模型对实验结果拟合，给出了离子在聚酰亚胺中产生潜径迹的能损阈值，实验给出的径迹形貌的电子能损效应曲线与热峰模型预言走势基本一致. 关键词： 离子辐照 潜径迹 红外光谱 热峰模型     

94MeV Xe离子辐照引起的薄膜硅光学带隙变化研究

室温下,用94MeV的Xe离子辐照纳米晶和非晶硅薄膜以及单晶硅样品,辐照量分别为1.0×1011,1.0×1012和1.0×1013ions/cm2。所有样品均在室温下用UV/VIS/NIR光谱仪进行检测分析。通过对比研究了纳米晶、非晶、单晶硅样品的光学带隙随Xe离子辐照量的变化。结果表明,不同结构的硅材料中Xe离子辐照引起的光学带隙变化规律差异显著:随着Xe离子辐照量的增加,单晶硅的光学带隙基本不变,非晶硅薄膜的光学带隙由初始的约1.78eV逐渐减小到约1.54eV,而纳米晶硅薄膜的光学带隙则由初始的约1.50eV快速增大至约1.81eV,然后再减小至约1.67eV。对硅材料结构影响辐照效应的机理进行了初步探讨。     

Modification of optical, chemical and structural response of CR-39 polymer by 50 MeV lithium ion irradiation

CR-39 polymer samples were irradiated with 50 MeV lithium ion beam; the fluence was varied in the range 10¹¹–10¹³ ionscm⁻². Irradiation effects were studied using UV–visible, FTIR spectroscopic and X-ray diffraction techniques. The observation of the recorded spectra shows that the detector is sensitive to swift ions irradiation and its UV absorption is influenced by the stopping power (dE/dx)_e. The FTIR spectra does not show any considerable changes due to the irradiation indicating that the detector is chemically stable. No appreciable change in the diffraction pattern of CR-39 polymer after irradiation upto the fluence level of 10¹³ ionscm⁻² is observed, showing its structural stability also.     

XRD and AFM study of radiation damage induced by swift heavy ions in Y3Al5O12 single crystals

Defects induced in Y₃Al₅O₁₂ single crystals by swift heavy ions are investigated by X-ray diffraction (XRD) and atomic force microscopy. The irradiation was performed at GANIL with 561 MeV ⁵¹Cr, 466 MeV ¹²⁸Te, and 957 MeV ²⁰⁸Pb ions. The XRD data reveal that the lattice strain increases with increasing electronic stopping power, whereas the hillock parameters (height and diameter) are not influenced by the electronic stopping power. According to our experimental data, for the same mean electronic stopping power, the hillock parameters are more pronounced for the lower range in contrast to swelling measurements. The experimental data show a strong increase in the hillock parameter at higher fluence, indicating the amorphization of Y₃Al₅O₁₂ single crystals.     

260～520 keV Krq+ (8≤q≤17)离子轰击Al靶产生的可见光辐射

低速高电荷态离子与金属表面相互作用,原子从靶材表面溅射,其中一部分处于激发态的溅射原子通过辐射退激产生可见光。在这一相互作用过程中,低速高电荷态离子从靶材表面捕获一个或多个电子进入其激发态,这些处于激发态的入射离子也会通过辐射退激产生可见光。研究表明,离子在靶材中的核阻止本领与溅射原子产额密切相关。为了更好地理解溅射原子的激发过程,认识低速高电荷态离子与金属相互作用过程中,溅射原子的激发概率与入射离子动能和势能之间的关联,研究了260～520 keV Krq+ (8≤q≤17)离子与Al靶相互作用过程中的可见光发射。给出了520 keV Kr13+ 与Al表面相互作用过程中,发射300～550 nm波长范围的发射光谱。实验结果包括溅射的Al原子在309.0和395.9 nm处的共振跃迁,Al+和Al2+分别在358.3和451.6 nm处的共振跃迁,以及Kr+在430.0,434.1,465.8和486.0 nm处的共振跃迁。还给出了谱线强度比值Y(309.0)/Y(395.9),Y(358.5)/Y(395.9),Y(452.8)/Y(395.9)随入射离子动能和势能的变化。结果表明：谱线强度比值均随入射离子动能的增加而增大,而比值Y(309.0)/Y(395.9)随势能的增加而减小。分析表明,在低速高电荷态离子与Al靶相互作用过程中,动能（电子阻止本领）和势能共同作用导致Al原子的激发,与激发态Al(4s)相比,电子布居较高激发态Al(3d)的概率随着离子电子阻止本领的增加而增大,而随着离子势能增加而减小。在低速高电荷态离子与金属表面相互作用过程中,入射离子在靶材中的核阻止本领影响溅射原子产额,而电子阻止本领与激发概率相关。在这一作用过程中,动能和势能共同决定溅射原子的激发概率,当动能和势能在同一数量级时,动能作用比势能作用小两个量级。