利用重离子辐照技术制备锂离子电池隔膜

用能量11.4MeV/u和注量1×108ions/cm2的197Au离子垂直辐照聚丙烯薄膜,通过电导测量法监测温度、硫酸浓度和重铬酸钾浓度对径迹蚀刻速率的影响,得到合适的蚀刻条件;成功制备出孔径范围在600—1000nm的重离子径迹聚丙烯孔膜,并用场发射扫描电镜对孔的形状及孔径大小进行了表征,对孔洞锥角的形成进行了分析,为重离子辐照技术制备锂离子电池隔膜提供了实验数据。     

各向异性静态随机存储器中的多位翻转分析研究

重离子实验结果表明,具有高线性能量转移(LET)或大角度入射的快重离子导致静态随机存储器(SRAM)中的多位翻转(MBU)比例增大,甚至超过单位翻转比例。单个离子径迹中的电荷可以沿着径向扩散数个微米,被临近的灵敏区收集后引起MBU。器件灵敏区的各向异性空间布局与离子入射方向共同影响测试器件的MBU图形特征。位线接触点的纵向隔离导致横向型成为主要的两位翻转图形;"L"型和"田"型分别是主要的三位翻转和四位翻转图形。最后,对SRAM抗MBU加固设计和实验验证方法进行了讨论。     

Raman spectrum study of graphite irradiated by swift heavy ions

Highly oriented pyrolytic graphites are irradiated with 40.5-Me V and 67.7-Me V ^112Sn-ions in a wide range of fluences： 1×10^11 ions/cm^2–1×10^14ions/cm^2. Raman spectra in the region between 1200 cm^-1 and 3500cm^-1 show that the disorder induced by Sn-ions increases with ion fluence increasing. However, for the same fluence, the amount of disorder is greater for 40.5-Me V Sn-ions than that observed for 67.7-Me V Sn-ions, even though the latter has a slightly higher value for electronic energy loss. This is explained by the ion velocity effect. Importantly, ～ 3-cm^-1frequency shift toward lower wavenumber for the D band and ～ 6-cm^-1 shift toward lower wavenumber for the 2D band are observed at a fluence of 1×10^14 ions/cm^2, which is consistent with the scenario of radiation-induced strain. The strain formation is interpreted in the context of inelastic thermal spike model, and the change of the 2D band shape at high ion fluence is explained by the accumulation of stacking faults of the graphene layers activated by radiation-induced strain around ion tracks. Moreover,the hexagonal structure around the ion tracks is observed by scanning tunneling microscopy, which confirms that the strains near the ion tracks locally cause electronic decoupling of neighboring graphene layers.     

电化学方法制备Si阵列微孔的工艺研究

对用电化学方法制备Si大孔阵列管坑工艺进行了初步探索。 通过对Si在KOH溶液中各向异性湿法蚀刻和在HF酸溶液中的电化学蚀刻过程中各种参数的摸索, 确定在室温下制备大孔阵列的最佳配比浓度, 蚀刻出符合要求的管坑阵列, 为进一步制备结构化闪烁屏奠定了实验基础。 The 3 D structures in silicon are increasingly coming to use in many fields. For example, the high resolution X ray digital imaging detector can be made by coupling CCD and the scintillating screen which is made by the array trenches filled with CsI(Tl). In the present work, we explored the technology of etching micro array on the n type silicon with high resistance. By studying the relative parameters of anisotropic etching of KOH and electro chemical etching of HF, the optimized concentration of HF was determined and the micro pore array trenches with 200 μm in depth were realized. The results establish an experimental base for further fabrication of the scintillating screen.     

离子径迹模板法制备纳米线

重离子辐照的高分子有机膜,经过适当的处理,可以作为模板制备金属和可溶性盐纳米线,此方法称为离子径迹模板法。介绍了用电化学沉积方法和过饱和溶液法制备金属纳米线和可溶性盐纳米线的基本原理和制各实例,同时还展望了离子径迹模板法制备纳米线的一些可能的应用。The polymer foils irradiated by heavy ions can be used as temptates to prepai nanowires and some inorganic salt nanowires. It is called ＂ion-track template method＂. Compared to other templates, such as AAO template and porous silicon, etched ion-track template is more convenient and flexible. The density of the pores can be easily controlled by changing the ion fluences and the diameter of the pores can be altered through changing the etching condition. The pores of the etched ion-track template are well aligned. We present some examples of preparing metallic nanowires and inorganic salt wires by electrochemical deposition and by supersaturation solution method, respectively. We also introduce some applications of nanowires prepared with ion-track template method.     

Angular dependence of multiple-bit upset response in static random access memories under heavy ion irradiation

Experimental evidence is presented relevant to the angular dependences of multiple-bit upset (MBU) rates and patterns in static random access memories (SRAMs) under heavy ion irradiation. The single event upset (SEU) cross sections under tilted ion strikes are overestimated by 23.9% 84.6%, compared with under normally incident ion with the equivalent linear energy transfer (LET) value of ～ 41 MeV/(mg/cm 2 ), which can be partially explained by the fact that the MBU rate for tilted ions of 30 is 8.5%-9.8% higher than for normally incident ions. While at a lower LET of ～ 9.5 MeV/(mg/cm 2 ), no clear discrepancy is observed. Moreover, since the ion trajectories at normal and tilted incidences are different, the predominant double-bit upset (DBU) patterns measured are different in both conditions. Those differences depend on the LET values of heavy ions and devices under test. Thus, effective LET method should be used carefully in ground-based testing of single event effects (SEE) sensitivity, especially in MBU-sensitive devices.     

云母模板中Cu纳米线的制备及其光学性质研究

利用快重离子辐照的单晶白云母片产生潜径迹,蚀刻得到直径在30—180 nm纳米孔道. 孔道形状依赖于蚀刻时间,蚀刻时间短得到圆柱形孔道,蚀刻时间长得到菱柱形孔道. 从而在云母模板孔道中电化学沉积得到不同直径和形状的Cu纳米线. 通过紫外可见光谱分析,发现铜纳米线的尺寸和形状影响其光学性质. 直径小于60 nm的近似为圆柱状Cu纳米线有一个明显的表面等离子体共振峰和一个微弱的次峰. 随着直径增加,菱柱状的Cu纳米线主峰有明显的红移,次峰逐渐增强. 同时利用扫描电子显微镜、X射线衍射对Cu纳米线的形貌和晶体结构特征进行了表征. 关键词： Cu纳米线 电化学沉积 光学性质 云母模板     

利用重离子径迹模版法制备出的钯纳米线阵列的表面等离激元共振现象研究(英文)

利用电化学沉积在重离子径迹模版中制备出了不同直径的一维钯纳米线。利用扫描电子显微镜、透射电子显微镜和X射线衍射等多多种手段对制得的钯纳米线进行了形貌和结构表征。利用紫外可见光谱仪分析了钯纳米线的光学响应,发现钯纳米线存在表面等离子体共振现象。随着纳米线直径和长度的增加,其表面等离子体共振峰位发生红移;通过改变光谱测试中激发光的入射角度,其表面等离激元共振模式会随着角度的增大而变多,这可能是在横向振动模式的基础上激发了沿纳米线长度方向振动的纵向模式。与此同时,基于时域有限差分法对钯纳米线的表面等离子体共振特性进行数值模拟,结果与实验符合较好。Palladium nanowires with varied diameters were fabricated using ion-track templates coupled with electrochemical deposition. The morphology and crystallographic structure were characterized with Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray diffraction (XRD). The plasmonic responses of the as-prepared nanowires were investigated by UV-Vis-NIR spectroscopy and the simulations based on the finite-difference time-domain algorithm. The results demonstrate that the surface plasmon resonances of Pd nanowire are sensitive to the wire geometry, but also influenced by the incidence angle of light. The frequency of the transverse dipolar plasmon resonance of nanowire arrays shifts within a wide range from visible to near infrared. With increasing of wires' diameter or length, the resonance peak shifts to the red. With increasing of incident angle, a new peak appears, which is possibly assigned to the excitation of the longitudinal resonance. In addition, numerical simulations disclose that propagating surface plasmon polaritons can be excited on the palladium nanowires and the wavelength of the resonance peak is in good agreement with the experimental results.     

25 MeV/u Kr辐照下PET薄膜的损伤机制研究

通过25 MeV/u 86 Kr离子辐照叠层结晶聚对苯二甲酸乙二醇酯膜（PET）, 在不同的电子能损（3.40-7.25 keV/nm）和离子注量(5×1011----3×1012 ions/cm2)辐照条件下, 对Kr离子在PET中引起的辐照损伤效应进行了研究。借助傅里叶变换红外光谱分析,通过对样品的红外吸收峰进行扣除基底后的Lorentz拟合,分析了与主要官能团对应的吸收峰强度的变化趋势, 研究了化学结构与组分在重离子辐照下的变化规律; 利用X射线衍射光谱仪测量, 研究了Kr离子在PET潜径迹中引起的非晶化过程,并通过对吸光度和非晶化强度随离子注量的指数衰减规律的分析, 获得了不同电子能损离子辐照PET时主要官能团的损伤截面和非晶化截面及对应的潜径迹半径。 At room temperature, polyethylene terephthalate(PET) foil stacks were irradiated by 25 MeV/u Kr ions in the electronic stopping power range(3.3--7.66 keV/nm) and the fluence range from 5×1011 to 3×1012 ions/cm2. The behaviour of the main function groups with fluence and electronic stopping power were studied by using Fourier transform infrared(FTIR) spectroscopy, the degradation of the function group was investigated with the Lorentz fitting subtracted baseline. The amorphous processes in the latent tracks of PET were studied by X ray diffraction(XRD) measurements. The Kr ion induced degradation cross section and amorphisation cross sections(radii) for different electronic energy loss were acquired from the experimental data(FT IR and XRD) by exponential decay function respectively.      

金纳米线阵列制备及其光谱特性

利用电化学沉积方法在重离子径迹模板中制备出直径从45 nm到200 nm, 长径比达700的金纳米线阵列, 利用扫描电子显微镜(SEM)和X射线衍射(XRD)对所制备金纳米线的形貌及晶体结构进行分析, 结果表明, 在1.5 V(无参比电极)沉积电压下所制备出的直径为200 nm金纳米线沿[100]晶向具有较好择优取向. 利用紫外-可见光谱(UV-Vis)对镶嵌在透明模板中平行排列的金纳米线阵列光学特性进行研究, 发现金纳米线直径为45 nm时, 其紫外可见光谱在539 nm处有强烈吸收峰, 随着金纳米线直径增加, 吸收峰红移, 当金纳米线直径达到200 nm时, 其吸收峰峰位移至700 nm. 结合金纳米颗粒相关表面等离子体共振吸收效应对实验结果进行了讨论.