目的为了有效降低空间大功率微波器件铝合金镀银表面的电子发射系数,提高空间大功率微波器件的微放电阈值。方法研究了铝基体上电化学镀银平板试样表面的两种粗糙化处理方法——微图形光刻法和直接湿化学腐蚀法,利用扫描电子显微镜和激...目的为了有效降低空间大功率微波器件铝合金镀银表面的电子发射系数,提高空间大功率微波器件的微放电阈值。方法研究了铝基体上电化学镀银平板试样表面的两种粗糙化处理方法——微图形光刻法和直接湿化学腐蚀法,利用扫描电子显微镜和激光扫描显微镜对两类表面处理得到的多孔平板样品的粗糙形貌进行了表征,利用电流法对其表面二次电子发射(SEY)特性进行了测试分析。结果所获得的规则阵列圆孔表面和大深宽比及随机分布的粗糙表面均能够显著降低镀银表面SEY,并且工艺重复性好。与平滑银表面相比,抑制效果最好的圆孔阵列样品表面能将SEY的最大值从2.2降到1.3,E1值从50 e V增加到100e V;随机刻蚀结构能将平滑银表面SEY的最大值从2.2降至1.1,E1提升至300 e V。基于孔隙内二次电子轨迹追踪的蒙特卡洛理论模拟方法,对两种典型样品的表面二次电子陷阱效应进行了理论分析,表面SEY特性模拟规律与测试数据一致。结论光刻和湿化学刻蚀工艺制备的银表面微形貌均能有效降低镀银表面的SEY,镀银表面粗糙化处理方法能够提高卫星大功率微波部件的微放电可靠性,并不会显著增加其插损。展开更多
O484.5 96063845金、铜、铂、银表面光学二次谐波参数的研究=Studies on the surface phenomenological parameterwith optical SHG from gold,copper,platinum and silver[刊,中]/雷洁,于群力,李祥生,张良民,苟增光(陕西师范大学物理系...O484.5 96063845金、铜、铂、银表面光学二次谐波参数的研究=Studies on the surface phenomenological parameterwith optical SHG from gold,copper,platinum and silver[刊,中]/雷洁,于群力,李祥生,张良民,苟增光(陕西师范大学物理系.陕西,西安(710062))//光子学报.-1995,24(4).-305-309以1.06μm激光为基频光,测量了金、铜、铂、银膜的反射二次谐波随基频光偏振角的变化,在b=-1的条件下拟合求得了这几种样品面谐波电流的唯象参数"α"值。图4参6(严兰)展开更多
单壁碳纳米管表面增强喇曼散射的新方法=New technique in SERS study on single wailed carbon nanotubes[刊,中]/方炎(首都师范大学北京市纳米光电子学重点实验室.北京(100037)),欧阳雨∥光电子·激光.—2004,15(6).—731-733 依...单壁碳纳米管表面增强喇曼散射的新方法=New technique in SERS study on single wailed carbon nanotubes[刊,中]/方炎(首都师范大学北京市纳米光电子学重点实验室.北京(100037)),欧阳雨∥光电子·激光.—2004,15(6).—731-733 依据碳纳米管独特的力学性能,在银表面直接研磨单壁碳纳米管(SWCNTs),在形成纳米级粗糙银表面的同时,SWCNTs管也吸附在银表面上,在银表面粗糙程度和SWCNTs厚度适中的区域得到了高质量的表面增强喇曼散射(SERS)谱。理论分析和实验结果表明,该方法是正确可行的。图2表1参10(于晓光)展开更多
Silver nanostructure compact aggregates on the surface of quartz glass substrates were synthesized by small gold seeds with the assistance of poly vinypyrrolidone (PVP) and irradiation of fluorescent lamp. The formati...Silver nanostructure compact aggregates on the surface of quartz glass substrates were synthesized by small gold seeds with the assistance of poly vinypyrrolidone (PVP) and irradiation of fluorescent lamp. The formation mechanism of silver nanostructure was proposed. The results show that both the PVP and the light irradiation are the keys to in-situ growth of silver nanostructure on quartz glass substrates. The silver nanostructure of the substrates which finally grow up to 150 nm after 20 h irradiation exhibits irregular shape, and some of nanoparticles stack to form bilayer. A new broad band appears in the absorption spectra of the substrates due to the interparticle dipole?dipole coupling of surface plasmon resonance response of the triangular silver nanoplate particles, which red shifts 600?800 nm as the particles grow up. The substrates have an emission band centered at 400 nm on their fluorescence spectra, and the fluorescence intensity shrinks as the average size of the silver nanostructure increases. The strongest SERS signal of SERS-active substrate is fabricated after 16 h.展开更多
Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin.It was found that both the amount of tannin and t...Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin.It was found that both the amount of tannin and the small triangular silver nanoplate seeds added to the growth solution are the key factors to modulation absorption band of triangular silver nanoplates.The optical in-plane dipole surface plasmon resonance (SPR) bands of these Ag nanoplates can be tuned from 608 nm to 980 nm via tannin deoxidization method.The formation mechanism of triangular silver nanoplates was proposed.The tannin deoxidization method realizes a convenient modulation of the absorption band of Ag nanostructures within the visible near-infrared (IR) region both in aqueous solvent and on substrates under mild conditions.展开更多
Stable and monodispersed silver nanoparticles were produced through a mild,convenient,one-pot method based on the reduction of silver nitrate in the presence of poly(amic acid) (PAA) as a stabilizer.The surface plasma...Stable and monodispersed silver nanoparticles were produced through a mild,convenient,one-pot method based on the reduction of silver nitrate in the presence of poly(amic acid) (PAA) as a stabilizer.The surface plasma band transition was monitored along with time in the reaction mixture for three sets of experiments by ultraviolet-visible spectroscopy.Analysis of the data with the Avrami equation yielded n exponent with values between 0.5 and 1.5,demonstrating three-dimensional heterogeneous nucleation and diffusion-controlled growth,accompanied by soft impingement effect.XRD and TEM analyses show a softly agglomerated polycrystalline state and a nearly spherical morphology (<50 nm) of nanoparticles.The FT-IR result indicates that the PAA molecular structure could be hardly influenced by the formation of nanoparticles.展开更多
Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of t...Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of the nano-structured Ag solid materials (NSS-Ag) were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectrometer. The NSS-Ag could be used as highly efficient surface-enhanced Raman scattering (SERS) active substrates. The common probe molecules Rhodamine 6G (R6G, 1×10-10 mol/L) were used to test the SERS activity on these substrates at very low concentrations. It is found that the SERS enhancement ability is dependent on the density of NSS-Ag. When the relative density of NSS-Ag is 83.87%, the materials reveal great SERS signal.展开更多
文摘目的为了有效降低空间大功率微波器件铝合金镀银表面的电子发射系数,提高空间大功率微波器件的微放电阈值。方法研究了铝基体上电化学镀银平板试样表面的两种粗糙化处理方法——微图形光刻法和直接湿化学腐蚀法,利用扫描电子显微镜和激光扫描显微镜对两类表面处理得到的多孔平板样品的粗糙形貌进行了表征,利用电流法对其表面二次电子发射(SEY)特性进行了测试分析。结果所获得的规则阵列圆孔表面和大深宽比及随机分布的粗糙表面均能够显著降低镀银表面SEY,并且工艺重复性好。与平滑银表面相比,抑制效果最好的圆孔阵列样品表面能将SEY的最大值从2.2降到1.3,E1值从50 e V增加到100e V;随机刻蚀结构能将平滑银表面SEY的最大值从2.2降至1.1,E1提升至300 e V。基于孔隙内二次电子轨迹追踪的蒙特卡洛理论模拟方法,对两种典型样品的表面二次电子陷阱效应进行了理论分析,表面SEY特性模拟规律与测试数据一致。结论光刻和湿化学刻蚀工艺制备的银表面微形貌均能有效降低镀银表面的SEY,镀银表面粗糙化处理方法能够提高卫星大功率微波部件的微放电可靠性,并不会显著增加其插损。
文摘O484.5 96063845金、铜、铂、银表面光学二次谐波参数的研究=Studies on the surface phenomenological parameterwith optical SHG from gold,copper,platinum and silver[刊,中]/雷洁,于群力,李祥生,张良民,苟增光(陕西师范大学物理系.陕西,西安(710062))//光子学报.-1995,24(4).-305-309以1.06μm激光为基频光,测量了金、铜、铂、银膜的反射二次谐波随基频光偏振角的变化,在b=-1的条件下拟合求得了这几种样品面谐波电流的唯象参数"α"值。图4参6(严兰)
文摘单壁碳纳米管表面增强喇曼散射的新方法=New technique in SERS study on single wailed carbon nanotubes[刊,中]/方炎(首都师范大学北京市纳米光电子学重点实验室.北京(100037)),欧阳雨∥光电子·激光.—2004,15(6).—731-733 依据碳纳米管独特的力学性能,在银表面直接研磨单壁碳纳米管(SWCNTs),在形成纳米级粗糙银表面的同时,SWCNTs管也吸附在银表面上,在银表面粗糙程度和SWCNTs厚度适中的区域得到了高质量的表面增强喇曼散射(SERS)谱。理论分析和实验结果表明,该方法是正确可行的。图2表1参10(于晓光)
基金Projects(10804101,60908023)supported by the National Natural Science Foundation of ChinaProject(2007CB815102)supported by the National Basic Research Program of ChinaProject(2007B08007)supported by the Science and Technology Development Foundation of Chinese Academy of Engineering Physics
文摘Silver nanostructure compact aggregates on the surface of quartz glass substrates were synthesized by small gold seeds with the assistance of poly vinypyrrolidone (PVP) and irradiation of fluorescent lamp. The formation mechanism of silver nanostructure was proposed. The results show that both the PVP and the light irradiation are the keys to in-situ growth of silver nanostructure on quartz glass substrates. The silver nanostructure of the substrates which finally grow up to 150 nm after 20 h irradiation exhibits irregular shape, and some of nanoparticles stack to form bilayer. A new broad band appears in the absorption spectra of the substrates due to the interparticle dipole?dipole coupling of surface plasmon resonance response of the triangular silver nanoplate particles, which red shifts 600?800 nm as the particles grow up. The substrates have an emission band centered at 400 nm on their fluorescence spectra, and the fluorescence intensity shrinks as the average size of the silver nanostructure increases. The strongest SERS signal of SERS-active substrate is fabricated after 16 h.
基金Project(10804101) supported by the National Natural Science Foundation of ChinaProject(2007CB815102) supported by the National Basic Research Program of ChinaProject(2007B08007) supported by the Science and Technology Development Foundation of Chinese Academy of Engineering Physics
文摘Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin.It was found that both the amount of tannin and the small triangular silver nanoplate seeds added to the growth solution are the key factors to modulation absorption band of triangular silver nanoplates.The optical in-plane dipole surface plasmon resonance (SPR) bands of these Ag nanoplates can be tuned from 608 nm to 980 nm via tannin deoxidization method.The formation mechanism of triangular silver nanoplates was proposed.The tannin deoxidization method realizes a convenient modulation of the absorption band of Ag nanostructures within the visible near-infrared (IR) region both in aqueous solvent and on substrates under mild conditions.
基金Project(10JJ5057)supported by the Hunan Provincial Natural Science Foundation of China
文摘Stable and monodispersed silver nanoparticles were produced through a mild,convenient,one-pot method based on the reduction of silver nitrate in the presence of poly(amic acid) (PAA) as a stabilizer.The surface plasma band transition was monitored along with time in the reaction mixture for three sets of experiments by ultraviolet-visible spectroscopy.Analysis of the data with the Avrami equation yielded n exponent with values between 0.5 and 1.5,demonstrating three-dimensional heterogeneous nucleation and diffusion-controlled growth,accompanied by soft impingement effect.XRD and TEM analyses show a softly agglomerated polycrystalline state and a nearly spherical morphology (<50 nm) of nanoparticles.The FT-IR result indicates that the PAA molecular structure could be hardly influenced by the formation of nanoparticles.
基金Project(10804101) supported by the National Natural Science Foundation of ChinaProject(2007CB815102) supported by the National Basic Research Program of ChinaProject(2007B08007) supported by the Science and Technology Development Foundation of Chinese Academy of Engineering Physics
文摘Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of the nano-structured Ag solid materials (NSS-Ag) were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectrometer. The NSS-Ag could be used as highly efficient surface-enhanced Raman scattering (SERS) active substrates. The common probe molecules Rhodamine 6G (R6G, 1×10-10 mol/L) were used to test the SERS activity on these substrates at very low concentrations. It is found that the SERS enhancement ability is dependent on the density of NSS-Ag. When the relative density of NSS-Ag is 83.87%, the materials reveal great SERS signal.
