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1.
利用溅射-气体-聚集-共沉积法,分别在方华膜和光学石英玻璃衬底上制备了Cu团簇嵌埋在CaF2介质中的Cu/CaF2复合团簇镶嵌薄膜样品。透射电镜分析表明,样品为多晶结构;样品的分光光谱仪测量和光Kerr响应表明,Cu金属的表面等离子体共振吸收频率明显依赖于样品中Cu团簇的大小,随着团簇尺寸的减小,榈共振吸收峰发生红移;并且在吸收峰位附近,表现出较大的第三级非线性系数。  相似文献   

2.
Ag-Cu离子注入SiO2玻璃后形成纳米颗粒的研究   总被引:3,自引:0,他引:3  
肖湘衡  蒋昌忠  任峰  付强 《功能材料》2005,36(10):1555-1557
Ag、Cu离子经200和110keV加速后分别以5×1016和1.5×1017ions /cm2的剂量在室温下先后注入到非晶SiO2玻璃中.注入后样品的光学吸收谱显示两个吸收峰,其峰位为407和569nm,分别对应单独Ag和单独Cu纳米颗粒的等离子体共振吸收峰,样品在还原-保护气氛下退火后吸收峰峰强明显增加.样品的透射电镜选区电子衍射花样含有Ag、Cu两套衍射环,透射电镜的明场像观察到大量的纳米颗粒呈现出中心亮斑特征.在样品倾转过程中,中心亮斑特征依然存在,证实这种现象是离子辐照产生的纳米空位团簇.扫描透射电子显微镜高角环形暗场像进一步证实了这一点.综上所述,样品中形成了单Ag和单Cu包裹空位团簇的纳米颗粒.  相似文献   

3.
利用蒸发-气体-聚集(EGA)共沉积方法,在有方华膜的电镜载网上制备了Fe-Ag及Co-Ag系列纳米磁性包埋团簇,通过控制蒸发电流等沉积条件,获得了不同团簇大小的样品。TEM/ED分析表明,当样品中Fe(Co)团簇尺寸较小时(分别为10nm和20nm),样品形貌表现为Fe(Co)团簇弥散地分布在Ag膜基质中,形成了Ag膜对Fe(Co)团簇的分隔与包埋;其结构分别为Fe、Ag多晶和Co、Ag多晶共存的形态。而当Fe(Co)团簇尺寸较大时(分别为90nm和50nm),样品中Ag原子也相对聚集,Ag膜没有形成对Fe(Co)团簇的完全包裹,在形貌上Fe-Ag样品呈现为“串状”,Co-Ag样品呈现为“花瓣状”;而在结构上则都表现为非晶形态  相似文献   

4.
Fe/Ag复合团簇镶嵌薄膜微观结构和磁性的研究   总被引:1,自引:0,他引:1  
提出了蒸发-气体-聚集(EGA)共沉积制备复合团簇镶嵌薄膜的新方法,并分别在方华膜和单晶Si(111)衬底上制备了系列Fe/Ag磁性复合团簇镶嵌薄膜样品,对所制备的样品进行了透射电镜分析,X射线能谱分析和振动样品磁强计磁性测量。结果表明,样品中Fe、Ag形成了相分离,为fcc结构的Ag和bcc结构的Fe多晶共存形态;对应于不同大小的Fe团簇样品,与块材相比,Fe团簇的晶格常数呈现出不同程度的收缩,  相似文献   

5.
基于溅射-气体-聚集(SGA)形成团簇的原理,提出了蒸发-气体-聚集(EGA)共沉积方法,并在方华膜载网上成功地制备了Fe-Cu纳米磁性包理团簇样品。TEM/ED分析表明,样品中Fe团簇被Cu原子所包裹,形成了以Fe团簇为芯,Cu膜为壳的良好的芯-壳式包埋结构。当衬底温度由25℃变化到200℃时,样品形貌由弥散状过渡到集团状,直至形成大的块状;其结构也相应的由Fe-Cu多晶共存变化为一种不规则的单晶形态。  相似文献   

6.
Fe—Cu包埋团簇的制备及其微观结构的研究   总被引:2,自引:0,他引:2  
王浩  赵子强 《功能材料》1996,27(5):449-451
基于溅射-气体-聚集(SGA)形成团簇的原理,提出了蒸发-气体-聚集(EGA)共沉积方法,并在方华膜载网上成功地制备了Fe-Cu纳米磁性包埋团簇样品。TEM/ED分析表明,样品中Fe团簇被Cu原子所包裹,形成了以Fe团簇为芯,Cu膜为壳的良好的芯-壳式包埋结构。当衬底温度由25℃变化到200℃时,样品形貌由弥散状过渡到集团状,直至形成大的块状;其结构也相应的由Fe-Cu多晶共存变化为一种不规则的单  相似文献   

7.
王浩 《真空与低温》1997,3(2):70-73
提出了溅射-气体-聚集共沉积制备金属/金属(介质)复合团簇镶嵌薄膜的新方法,并利用该方法成功地在方华膜衬底上制备了系列Fe/Ag及CaF2复合团簇镶嵌薄膜样品。透射电镜分析结果表明,样品中Fe(Cu)团簇都较好地镶嵌于Ag(CaF2)基质中,其结构为两种材料的多晶共存形态。进一步分析发现,与块材相比,Fe/Ag样品中Fe团簇晶格常数呈现出不同程度的收缩,而Cu/CaF2样品中Cu团簇晶格常数则呈现出不同程度的膨胀。运用附加压力的模型对该现象进行了解释。  相似文献   

8.
采用基于密度泛函理论(DFT)的Dmol3程序广义梯度近似PBE泛函,系统研究了Con(n =1~5)团簇及其对分子氧(O2)(垂直和平行)吸附后的ConO2团簇几何结构、稳定性和电子性质。结果表明:Con团簇的结合能随团簇数目的增加而增大,变化趋势趋于平缓,稳定性增强;分子氧在Con团簇顶位、桥位、空位的吸附稳定性、Co—O键长、O—O键长、分子氧的电荷转移都随团簇数目增大呈现规律性变化,说明分子氧被活化;Con团簇和分子氧之间的电荷转移越多,相互作用越强,吸附能和结合能也越大;分子氧垂直吸附型Co2O2 B团簇的吸附能和结合能最强,分别是-6.744 eV和4.611 eV,分子氧所得电荷最强为 -1.130 e。  相似文献   

9.
采用分子动力学方法对含有100万个Na原子的液态金属大系统在凝固过程中纳米级团簇结构的形成与演变进行了模拟研究。采用Honeycutt-Andersen(HA)键型指数法和原子团类型指数法(CTIM)的基本原子团表征了各种类型大团簇的结构组态。结果显示:在液态金属Na凝固过程中,与1551键型密切相关的(13364),(131102),(14248)等3种基本原子团及其组合在微观结构转变中起着最重要的作用;凝固过程中形成的纳米级大团簇结构是由大小不同的中、小团簇及各种基本原子团相互连接而成,且大团簇结构内各种基本原子团的中心原子都是相互呈单键连接或多键连接,团簇结构内呈多键结合的中心原子的数目越多,该团簇越稳定;系统中各种类型团簇结构的数目具有明显的幻数特性,与Knight等人的实验结果甚为相符。  相似文献   

10.
研究了Cu离子掺杂对层状钙钛矿结构锰氧化物La1.2Ca1.8Mn2O7电磁性能的影响.观察到低含量Cu掺杂样品铁磁性减弱,出现金属-绝缘转变与团簇玻璃态行为;高含量Cu掺杂样品为绝缘体,出现顺磁与自旋玻璃态行为.相对小极化子跃迁模型或热激活半导体带隙模型而言,可变程跃迁模型更好地描述了载流子在顺磁状态的电输运机制.  相似文献   

11.
Cu/SiO2 nano-composite thin films were prepared by a sol–gel method. The structure and optical property of the films were investigated with a special emphasis on the influences of Cu content. Cu particles were basically spherical and dispersed in the SiO2 matrix. The optical absorption peaks due to the surface plasmon resonance of Cu particles were observed in the wavelength range of 550–600 nm. The absorption property is enhanced with increasing Cu content, showing a maximum value in the films with 30 at.% Cu. Increasing Cu content above 30 at.% results in a decrease in absorption intensity. The absorption peak shows a red-shift trend with increasing Cu content from 5 to 30 at.% and then turns to blue-shift by further increasing the Cu content from 30 to 35 at.%. The band gap Eg decreases with increasing Cu content from 10 to 30 at.% but increases by further increasing Cu content.  相似文献   

12.
Q.X. Zhao 《Materials Letters》2008,62(25):4140-4142
Cu films are deposited on Si (001) substrates under various Ar deposition pressures by radio frequency (RF) magnetron sputtering. The crystallinity and orientation of Cu films is characterized by employing X-ray diffraction technique. It is found that the intensities of Cu peaks change with Ar pressure systematically, and ~ 5 Pa is the most favorable Ar pressure to get highly (111) oriented Cu films. Electron temperature and optical emission spectrum (OES) of plasma plume are measured using the double Langmuir probes, a monochromator and a PMT detector. We found that the electron temperature decreases exponentially with increasing deposition pressure, and there are strong correlations of optical emission, electron temperature, and the microstructure of Cu films. We define a Cu atomic relevant coefficient to describe the crystallinity and orientation of Cu films prepared under various pressures. This work may provide a method to understand the crystallinity and orientation evolution of the film prepared by sputtering via investigating optical emission and electron temperature.  相似文献   

13.
Baba K  Hayashi K  Syuaib I  Yamaki K  Miyagi M 《Applied optics》1997,36(11):2421-2426
Gold (Au), silver (Ag), copper (Cu), and aluminum (Al) island films have been investigated for write-once optical data storage media with the high reflectance and the large reflectance changes induced by laser irradiation. We show that, of the four, the Ag and the Cu island films are the most useful as WO media at 800 nm. The Al island films are useful for a shorter wavelength region. The optical and structural changes in laser-written regions on the island films have also been investigated experimentally. It appears that the metal-island films show great potential as optical data storage media for compact-disk-compatible write-once optical disks.  相似文献   

14.
The optical response of nanocomposite thin films formed by Cu nanoparticles (NPs) embedded in amorphous aluminium oxide (Al(2)O(3)) prepared by pulsed laser deposition (PLD) in vacuum is studied in order to investigate the possible existence of reactive processes on the Cu NPs during their covering with Al(2)O(3). The study is performed as a function of the laser fluence on the Al(2)O(3) target (0.6-4.6?J?cm(-2)), while the laser fluence for Cu ablation is kept constant (1.8?J?cm(-2)). The structural analysis of the films shows that they are formed by a high density of NPs with average dimensions in the 4.9-5.9?nm range. The optical response of the films has been followed in situ by real-time reflectivity measurements at 633?nm and after deposition by transmission measurements as a function of wavelength around the surface plasmon resonance (SPR). For low laser fluences on the Al(2)O(3) target, the absorption spectrum is dominated by a well-defined SPR absorption band at 1.9?eV. As the laser fluence is increased, the intensity of the absorption band associated with the SPR decreases and shifts to 2.1?eV. The films deposited at low fluences contain metallic Cu NPs and, as the laser fluence increases sputtering of Cu from the NPs and mixing of the species from the Al(2)O(3) deposition with the Cu from the NPs surface takes place. The latter process leads to the formation of an Al-Cu oxide cover on the Cu NPs. The present results provide evidence for mixing of species from the host and Cu at the surface of the NPs, and it is shown how the degree of mixing depends on the laser fluence used to ablate the Al(2)O(3) host target.  相似文献   

15.
This paper reports on the structural and optical properties of ZnCuO thin films that were prepared by co-sputtering for the application of p-type-channel transparent thin-film transistors (TFTs). Pure ceramic ZnO and metal Cu targets were prepared for the co-sputtering of the ZnCuO thin films. The effects of the Cu concentration on the structural, optical, and electrical properties of the ZnCuO films were investigated after their heat treatment. It was observed from the XRD measurements that the ZnCuO films with a Cu concentration of 7% had ZnO(002), Cu2O(111), and Cu2O(200) planes. The 7% Cu-doped ZnO films also showed a band-gap energy of approximately 2.05 eV, an average transmittance of approximately 62%, and a p-type carrier density of approximately 1.33 x 10(19) cm-3 at room temperature. The bottom-gated TFTs that were fabricated with the ZnCuO thin film as a p-type channel exhibited an on-off ratio of approximately 6. These results indicate the possibility of applying ZnCuO thin films with variable band-gap energies to ZnO-based optoelectronic devices.  相似文献   

16.
ZnO films codoped by copper and nitrogen were prepared by magnetron cosputtering. The effects of this codoping on the structural and optical properties of ZnO films were systematically studied. The results show that Cu–N codoping didn’t affect the optimal orientation. Cu–N codoping can enlarge the grain size, enhance the crystallinity, reduce the stress and lead to denser and smoother surface. A significant red shift of absorption edge and gap-narrowing effect resulting from codoping were found in ZnO films. Cu-doping, N-doping, and oxygen vacancy are the main factors leading to property modification of the ZnO films. By Cu–N codoping, we can modulate the microstructure and optical properties of ZnO films in a wider range.  相似文献   

17.
p-Type Cu-Al-O films are successfully prepared by using radio frequency magnetron reactive co-sputtering deposition with Cu and Al metallic targets. Stoichiometric Cu/Al atomic percentage ratio has been achieved. The films show good transmittance in the range of 20-80% with an average thickness of 250 nm. The optical direct band gaps of the films are found in the range of 2.9-3.3 eV depending on the aluminum content. Blue-shift in absorption edge and optical band gap broadening effect are found with the increase of Al content in the films.  相似文献   

18.
采用直流磁控溅射方法在玻璃衬底上室温生长了AZO/Cu双层薄膜,Cu层厚度控制在9nm,研究了AZO层厚度对薄膜电学和光学性能的影响。当AZO层厚度为20~80nm时,AZO/Cu双层薄膜具有良好的综合光电性能,方块电阻为12~14Ω/sq,可见光平均透过率为70~75%,品质因子为2×10-3~5×10-3Ω-1。AZO/Cu双层薄膜可以观察到Cu(111)和ZnO(002)的XRD衍射峰。通过退火研究表明,AZO/Cu双层薄膜的光电性能可在400℃下保持稳定,具有良好的热稳定性。本研究制备的透明导电AZO/Cu双层薄膜具有室温制程、综合光电性能良好、结晶性能较好、稳定性高的优点,可以广泛应用于光电器件透明电极及镀膜玻璃等领域。  相似文献   

19.
杨靖安  张俊英  李春芝 《功能材料》2012,43(3):398-400,404
采用直流磁控溅射,靶材为金属铜靶,调节氧气和氩气流量,制备了以石英玻璃为基底颗粒大小在20~50nm之间的Cu和Cu2O纳米薄膜,研究了大肠杆菌与纳米铜系氧化物薄膜的相互作用。通过紫外可见分光光度计,掠入射小角X射线衍射(GIXRD),SEM分别对样品的光学性能、晶体结构、形貌特征进行了研究,发现纳米Cu和Cu2O薄膜均对大肠杆菌具有强抑制作用。在光照下,Cu2O薄膜除了具有金属离子抗菌效应外,光催化抗菌效应表现强烈;Cu薄膜表面有部分被氧化为Cu2O,有助于协同抗菌。  相似文献   

20.
The Cu particles or clusters dispersed mesoporous SiO2 composite films were prepared by a new method: first the matrix SiO2 films were prepared by sol–gel process combined with the dip-coating technique, and then they were soaked in Cu(NO3)2 solutions followed by γ-ray irradiation at room temperature and in ambient pressure. Thus, the prepared Cu/SiO2 composite films were examined by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and optical absorption spectroscopy. It has been shown that the Cu particles grown within the porous SiO2 films are very small, and they are isolated and dispersed from each other with very narrow size distributions. With the Cu particles size changing, an interesting peak shift was observed in the optical absorption measurement. Possible mechanisms of this behavior are discussed in this paper.  相似文献   

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