激光加热碳、金平面靶等离子体膨胀过程

利用软X射线条纹相机与针孔成象装置相结合,测得了碳、金平面靶靶面X射线时、空分辨图象,从而推算出靶面等离子体膨胀平均速度分别为(碳):5.11×10⁷cm/s,(金):6.13×10⁷cm/s。实验用1.06μm的钕玻璃激光轰击靶面,X射线能谱范围为0.1—10keV。测量在激光功率密度≈10¹⁴W/cm²的情况下进行。 关键词：     

纯锆上离子注入钇和镧后的表面分析

用金属蒸汽真空弧源，以40kV加速电压对纯锆样品分别进行了10¹⁶—10¹⁷/cm²的钇、镧离子注入，注入温度约为130℃.然后对注入样品进行表面分析.x射线光电子能谱分析表明，注入的钇以Y₂O₃形式存在，镧以La₂O₃形式存在.俄歇电子能谱表明，纯锆基体表面的氧化膜厚度随着离子注入剂量的增加而增加，当离子注入剂量达到10¹⁷/cm²时，氧化膜的厚度达到了最大值.卢瑟福背散射显示镧层的厚度约为30nm，同时直接观察到当离子注入剂量为(La+Y)10¹⁷/cm²时，纯锆样品表面发生了严重的溅射. 关键词： 纯锆 钇和镧离子共注入 卢瑟福背散射 x射线光电子能谱     

Ti离子注入和退火对ZnS薄膜结构和光学性质的影响

利用真空蒸发法在石英玻璃衬底上制备了ZnS薄膜,将能量80 keV,剂量1×10¹⁷ cm^-2的Ti离子注入到薄膜中,并将注入后的ZnS薄膜进行退火处理,退火温度500—700 ℃.利用X射线衍射（XRD）研究了薄膜结构的变化,利用光致发光（PL）和光吸收研究了薄膜光学性质的变化.XRD结果显示,衍射峰在500 ℃退火1 h后有一定程度的恢复;光吸收结果显示,离子注入后光吸收增强,随着退火温度的上升,光吸收逐渐降低,吸收边随着退火温度的提高发生蓝移;PL显示,薄 关键词： ZnS薄膜 离子注入 X射线衍射 光致发光     

厚度对MOCVD生长InN薄膜位错特性与光电性质的影响

研究了金属有机物化学气相沉积法制备的不同厚度InN薄膜的位错特性与光电性质.基于马赛克微晶模型,通过X射线衍射非对称面摇摆曲线测量,拟合出样品刃型位错密度分别为4.2×10¹⁰cm^-2和6.3×10¹⁰cm^-2,并发现样品的微晶扭转角与位错密度随薄膜厚度增加而减小.通过室温霍尔效应测量得到样品载流子浓度分别为9×10¹⁸cm^-3和1.2×10¹⁸cm关键词： 氮化铟 位错 载流子起源 局域态     

钴离子注入对二氧化钛晶体的结构和光学性能的影响

采用离子注入法制备了钴离子掺杂的金红石相TiO₂样品;离子注入能量、注量分别为40 keV(1×10¹⁶cm^-2),80 keV(5×10¹⁵,1×10¹⁶,5×10¹⁶,1×10¹⁷cm^-2),120 keV(1×10¹⁶cm^-2). 通过XRD,XPS和UV-Vis等手段对掺杂前后样品的结构和光学性能进行了表征,分析了掺杂元素在金红石TiO₂中的存在形式. XRD测试表明随着注入能量的增加晶体的损伤程度增加. UV-Vis测试表明掺杂后所有样品在可见光区的吸收增强; 并且随着注量的增加,注量为5×10¹⁵cm^-2到5×10¹⁶cm^-2范围内注入样品的光学带隙逐渐变小. 关键词： 钴 二氧化钛 离子注入 掺杂     

Ag离子注入非晶SiO2的光学吸收、拉曼谱和透射电镜研究

能量为200keV的Ag离子，以1×10¹⁶，5×10¹⁶，1×10¹⁷ cm^-2的剂量分别注入到非晶SiO₂玻璃，光学吸收谱显示：注入剂量为1×10¹⁶ cm^-2的样品的光吸收谱为洛伦兹曲线，与Mie理论模拟的曲线形状一致；注入剂量较大的5×10¹⁶，1×10¹⁷ cm^-2的谱线共振吸收增强，峰位红移并出现伴峰. 透射电镜观察分析表明，注入剂量不同的样品中形成的纳米颗粒的大小、形状、分布都不同，注入剂量较大的还会产生明显的表面溅射效应，这些因素都会影响共振吸收的峰形、峰位和峰强. 当注入剂量达到1×10¹⁷ cm^-2时，Ag纳米颗粒内部可能还形成了杂质团簇. 关键词： 离子注入 纳米颗粒 共振吸收 红移     

激光加热Cu和NaF靶产生的1.2keV区X射线转换效率的测量

介绍了激光加热Cu靶和NaF靶发射的在1.2keV区X射线转换效率的测量方法和实验结果。结果表明,在激光辐照功率密度为1×10¹³—1×10¹⁴W·cm^-2条件下,激光波长为1.06μm或0.53μm时,Cu等离子体发射的1.2KeV区X射线的转换率为NaF等离子体的4—5倍;对此两种等离子体,激光波长为0.53μm的X射线转换效率是波长为1.06μm的2倍左右。 关键词：     

氮原子、分子与团簇离子注入Si(111)的特性研究

用椭偏仪、傅氏变换红外吸收谱(FTIR)、X射线光电子能谱(XPS)以及原子力显微镜(AFM)对N⁺₁,N⁺₂,N⁺₁₀离子高剂量(1.7×10¹⁷ions/cm²)注入Si(111)的表面进行测试分析,发现三种不同尺度的离子注入后,均使Si由复折射率变化为实折射率,表面出现含氮硅键的介质层.但其表面形貌各异:N^{+关键词： 氮团簇注入 表面特性}     

X射线探测器的脉冲标定技术

利用强流电子束技术产生通量密度为10¹⁸—10¹⁹X-ray photon/sr·s的脉冲CuKX射线源,标定PIN型硅二极管半导体探测器对X光子的脉冲灵敏度。用绝对X射线监测器——P10气体脉冲电离室作为脉冲X射线通量密度的标准。脉冲电荷自动测量仪由微处理机进行程序控制,并予以实时校准。该电离室测量通量密度的精度为±5％,适用的能通量率范围可达4×10^-9—2×10²W/cm²,适用的光子能量范围为1.5—10keV,标定探测器的精度为±7.0％,并发现PIN型硅二极管的脉冲灵敏度比稳态X射线束标定的灵敏度高30％左右。 关键词：     

类金刚石膜不同能量下的离子注入

本文对等离子体气相沉积法制备的类金刚石膜(a-C:H)进行了离子注入研究。注入剂量固定为5×10⁵Ar/cm²,注入能量分别为50,100,140和180keV。离子注入前后分别作了红外吸收谱,Raman谱,光学能隙,氢含量和电阻率的测量。结果表明,注入离子破坏了膜中的C—H键,sp²和sp³态都减少,而(sp²/sp³)比值增大;光学能隙E_opt,电阻 关键词：     

A Novel Pyrene Fluorescent Sensor Based on the π–π Interaction Between Pyrene and Graphene of Graphene–Cadmium Telluride Quantum Dot Nanocomposites

In this article, water-soluble graphene–cadmium telluride quantum dot nanocomposites were fabricated through the synthesis of cadmium telluride quantum dots in the presence of graphene aqueous dispersion. It was found that pyrene could remarkably quench fluorescence of graphene–cadmium telluride quantum dot nanocomposites. On this basis, a novel method for the determination of pyrene was developed. Factors affecting the pyrene detection were investigated, and the optimum conditions were determined. Under the optimum conditions, a linear relationship could be established between the quenching of fluorescence intensity of graphene–cadmium telluride quantum dot nanocomposites and the pyrene concentration in the range of 6.00 × 10^?8–2.00 × 10^?6 mol L^?1 with a correlation coefficient of 0.9959. The detection limit was 4.02 × 10^?8 mol L^?1. Furthermore, the nanocomposites were applied to practical determination of pyrene in different water samples with satisfactory results.     

Fluence dependant formation of <Emphasis Type="Italic">β</Emphasis>-SiC by ion implantation and thermal annealing

The β-SiC nanocrystals were synthesized by the implantation of carbon ions (C⁻) into silicon followed by high-temperature annealing. The carbon fluences of 1×10¹⁷, 2×10¹⁷, 5×10¹⁷, and 8×10¹⁷ atoms/cm² were implanted at an ion energy of 65 keV. It was observed that the average size of β-SiC crystals decreased and the amount of β-SiC crystals increased with the increase in the implanted fluences when the samples were annealed at 1100 °C for 1 h. However, it was observed that the amount of β-SiC linearly increased with the implanted fluences up to 5×10¹⁷ atoms/cm². Above this fluence the amount of β-SiC appears to saturate. The Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, and X-ray diffraction (XRD) techniques were used to characterize the samples.     

Changes in Structural and Optical Properties of Polycarbonate Induced by Ag+ Ion Implantation

Transparent polycarbonate samples were implanted with 1 MeV Ag⁺ ions to various doses ranging from 5 × 10¹⁴ to 3 × 10¹⁶ ions cm^?2 with a beam current density of 900 nA cm^?2. Modification in the structure of polycarbonate as a function of the implantation fluence was investigated using micro-Raman spectroscopy, glancing angle X-ray diffraction, and UV-Vis spectroscopy. Raman spectroscopy pointed toward the formation of graphite structures/clusters due to the ion implantation. UV-Vis absorption analysis suggests the formation of a carbonaceous layer and a drastic decrease in optical band gap from 4.12 eV to 0.50 eV at an implanted dose of 3 × 10¹⁶ ions cm^?2. The correlation between the decrease in band gap and the structural changes is discussed.     

Corrosion behavior of tin ions implanted zirconium in 1N H2SO4

In order to study the effect of tin ion implantation on the aqueous corrosion behavior of zirconium, specimens were implanted with tin ions to a fluence ranging from 1 × 10²⁰ to 5 × 10²¹ ions/m², using a metal vapor vacuum arc source (MEVVA) at an extraction voltage of 40 kV. The valence states and depth distributions of elements in the surface layer were analyzed by X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES) respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the micro-morphology and microstructure of tin-implanted samples. When the fluence was greater than 1 × 10²⁰ ions/m², many small tin balls were produced in the implanted surface. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted zirconium in a 1N H₂SO₄ solution. It was found that a significant improvement was achieved in the aqueous corrosion resistance of zirconium implanted with 1 × 10²⁰ ions/m². When the fluence is higher than 1 × 10²⁰ ions/m², the corrosion resistance of zirconium implanted with tin ions decreased compared with that of the non-implanted zirconium. Finally, the mechanism of the corrosion behavior of the tin-implanted zirconium is discussed.     

Magnetic structure of ion-implanted bubble garnets

The surface magnetic structure of bubble garnet films implanted with 80 keV Ne⁺ ions has been investigated by conversion-electron Mössbauer spectroscopy in conjunction with backscattered X-ray Mössbauer spectroscopy. For lower doses (～1–3 × 10¹⁴Ne⁺cm^-2) a ferrimagnetic component with in-plane magnetization coexists with a smaller paramagnetic phase in the implanted layer; for a dose of 5 × 10¹⁴Ne⁺cm^-2 only a paramagnetic phase is observed.     

Theoretical analysis of transmission performance of Pr3+–Er3+-co-doped telluride Fiber amplifiers for WDM systems

In this paper, we explore for the first time the possibility of Pr³⁺–Er³⁺-co-doped telluride amplifiers for a Wavelength Division Multiplexing (WDM) transmission system. We analyze the gain characteristics of the Pr³⁺–Er³⁺-co-doped telluride amplifiers co-pumped by 1010 and 1480 nm lasers, by employing an amplifier model which is based on propagation and population-rate equations. It is shown that employing amplifiers with an Er³⁺ ion concentration of 8×10²⁵ ions/m³ and a Pr³⁺ ion concentration of 4×10²⁵ ions/m³ and active fiber length of 1.1 m, the largest transmission distance of the WDM system can reach 1620 and 1380 km for 1330 and 1550 nm channels, respectively, with BER lower than 1×10^?9.     

Structural and Chemical Modification in a Polymer by Metal Ion Implantation

Physical and chemical properties changes in a polymer have been studied for polycarbonate (PC) implanted with 100 keV Ni⁺ ions with varying fluence from 1 × 10¹⁴ to 1 × 10¹⁶ ions/cm². The changes in the surface morphology and composition have been observed with atomic force microscopy (AFM) and X-ray diffraction (XRD). The ions implanted induce changes in topography of PC and indicate that the roughness increases dramatically with ion fluence. Implanted metal ions shows direct evidence of compound formation on the surface. The chemical changes in the surface region have been carried out by Raman Spectroscopy and UV-VIS spectroscopy. UV-VIS absorption analysis indicates a drastic decline in optical band gap from 5.46 eV to 1.76 eV at an implanted dose of 1 × 10¹⁶ ions/cm². It could be shown that the partial destruction of chemical bonding under ion implantation leads to the creation of new amorphous and graphite-like structures, which is confirmed by Raman spectroscopy.     

Ni离子注入多晶ZrO2的表面电性能和结构

对氧化钇(Y₂O₃)部分稳定氧化锆(ZrO₂)样品在室温下进行了Ni离子注入(140kev,5×10¹⁵-2×10¹⁷ios/cm²)和热退火处理.应用电学测量,Rutherford背散射技术(RBS),X射线光电子能谱(XPS)和喇曼光谱方法研究了Ni离子注入多晶ZrO₂的表面电性能,注入层结构及其热退火的影响。     

Effect of Fe-ion implantation doping on structural and optical properties of CdS thin films

We report on effects of Fe implantation doping-induced changes in structural, optical, morphological, and vibrational properties of cadmium sulfide thin films. Films were implanted with 90 keV Fe⁺ ions at room temperature for a wide range of fluences from 0.1×10¹⁶ to 3.6×10¹⁶ ions cm⁻² (corresponding to 0.38–12.03 at.% of Fe). Glancing angle X-ray diffraction analysis revealed that the implanted Fe atoms tend to supersaturate by occupying the substitutional cationic sites rather than forming metallic clusters or secondary phase precipitates. In addition, Fe doping does not lead to any structural phase transformation although it induces structural disorder and lattice contraction. Optical absorption studies show a reduction in the optical band gap from 2.39 to 2.17 eV with increasing Fe concentration. This is attributed to disorder-induced band tailing in semiconductors and ion-beam-induced grain growth. The strain associated with a lattice contraction is deduced from micro-Raman scattering measurements and is found that size and shape fluctuations of grains, at higher fluences, give rise to inhomogeneity in strain.