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1.
Metal nanocluster composite glass prepared by 200 keV Ag ions' implantation into silica with dose of 2 × 1017 ions/cm2 has been studied. The formation of sandwiched nanocluster-nanovoid-nanocluster structures has been evidenced by in situ transmission electron microscopy experiment (TEM). Fast nonlinear optical refraction and nonlinear optical absorption coefficients were measured at 532 nm and 1064 nm of wavelength by the Z-scan technique. The third-order nonlinear susceptibility χ(3) of this kind of sample was determined to be 4.0 × 10−8 esu at 532 nm and 9.0 × 10−8 esu at 1064 nm, respectively. 相似文献
2.
Metal nanoparticles synthesized by sequentially ion-implanted Ag and Cu into silica glasses have been studied. Third-order nonlinear optical properties of the nanoclusters were measured at 1064 nm excitations using the Z-scan technique. Results of the investigation of nonlinear refraction by the off-axis Z-scan configuration are presented and the mechanisms responsible for the nonlinear response discussed. Curve-fitting analysis, based on MATLAB features, for Ag/Cu optical limiting experiment has been used. Results show that Ag/Cu nanoclusters display a refractive optical limiting effect at 1064 nm. 相似文献
3.
Synthesis of metal nanoparticles by ion implantation has a number of advantages. Nevertheless, certain remaining difficulties must be overcome in order to optimize the characteristics of ion-implanted nanocomposites. The principle among these are the lack of control over the size distribution and position of the precipitates within the implanted layer. Two-dimensionally ordered arrangements of Ag nanoparticles are formed in Ag-implanted silica glass by post-implanted Cu ions. The spherical Ag nanoparticles are formed to align at the same deep depth in the silica. Cross-sectional transmission electron microscopy revealed that the Ag nanoparticles are a size of 35-48 nm in diameter. The evolution of nanoparticles is characterized by transmission electron microscopy. 相似文献
4.
X.D. Zhang C.L. Liu M.L. Guo W.X. Li L.J. Yin Y.Y. Lü Z. Wang P. Wu T.Y. Liu M.K. Li B. Yuan 《Optical Materials》2008,30(9):1382-1386
Cu nanoparticles (NPs) have been fabricated in Si3N4/Si by 45 keV Cu ion implantation at a dose of 1 × 1017 cm−2, and followed by thermal processing at 500–700 °C in air. Techniques, such as atomic force microscopy and X-ray diffraction are used to confirm the formation and evolutions of Cu NPs. The surface plasmon resonance of Cu NPs has been investigated by reflection spectroscopy. The orange–red luminescence band (600 nm) with high fluorescence quantum efficiency has been observed in Cu NPs, and its possible mechanism has also been discussed. 相似文献
5.
The optical propagation property of a planar waveguide with a periodic nanoparticle grating layer is characterized by using sliding prism method. Here, Cu nanoparticle grating was fabricated on a-SiO2 substrate by periodic heavy-ion irradiation technique. The pitch of these gratings was 2 μm and 3 μm, respectively. The flux and fluence were at the range of 6-10 μA/cm2 and 6 × 1016-1 × 1017 ions/cm2, respectively. The grating effect, mainly including the mode selection effect, is observed. The effect depends on the pitch of the grating and the morphology of nanoparticles. The propagation loss of the waveguide induced by nanoparticle layer is evaluated. 相似文献
6.
Optical absorption and nonlinear absorption were studied for Ag nanoparticle composite. Negative Ag− ion with 60 keV were applied for implanting into amorphous-SiO2 at a flux 3 μA/cm2 to total fluences ranging from 3 × 1016 to 1 × 1017 ions/cm2. Absorption spectra of Ag-implanted amorphous-SiO2 showed a surface plasmon peak resulting from formation of nanoparticles. The strength of the resonance reflected from the local electric field inside the nanoparticle induced by an external electric field. Nonlinear optical constants were evaluated by the z-scan method with a tunable femtosecond laser system. The strength of the nonlinearity also reflected from the local electric field. Nonlinear absorption coefficients exhibit a maximal value of −3.6 × 103 m/GW for Ag:SiO2 at 420 nm (2.95 eV), around the surface plasmon resonance. 相似文献
7.
G.X.Cai F.Ren X.H.Xiao L.X.Fan X.D.Zhou C.Z.Jiang- Key Laboratory of Acoustic Photonic Materials Devices of Ministry of Education Wuhan University Wuhan China 《材料科学技术学报》2009,25(5)
Ion implantation is a powerful method for fabricating nanoparticles in dielectric.For the actual application of nanoparticle composites,a careful control of nanoparticles has to be achieved.In this letter,the size,distribution and morphology of Ag nanoparticles are controlled by controlling the ion current density,ion implantation sequence and ion irradiation dose.Single layer Ag nanoparticles are formed by Ag+ion implantation at current density of 2.5μA/cm2.By Ag and Cu ions sequential implantation,the siz... 相似文献
8.
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
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
9.
Metal plasma ion implantation has being successfully developed for improving the electronic and optical properties of semiconductor materials. Prior to deposition, a TiO2 colloidal suspension was synthesized by microwave-induced thermal hydrolysis of the titanium tetrachloride aqueous solution. The TiO2 thin film was optimized to obtain a high-purity crystalline anatase phase by calcinations at 550 °C. The TiO2 coating was uniform without aggregation, which provided good photo conversion efficiency. Ag ion implantation into the as-calcined TiO2 thin films was conducted with 1 × 1015 ~ 1 × 1016 ions/cm2 at 40 keV. The peak position and intensity of the photoluminescence and UV-Vis absorption spectra are quite sensitive to Ag doping. The optical characterization showed a shift in optical absorption wavelength towards infrared ray side, which was correlated with the structure variation of the Ag+ implanted TiO2. Due to the strong capability of forming compounds between the energetic silver ions and TiO2, the photoluminescence emission and UV-Vis absorption efficiencies were improved. 相似文献
10.
X.D. ZhangJ.F. Xi Y.Y. ShenL.H. Zhang F. ZhuZ. Wang Y.H. XueC.L. Liu 《Optical Materials》2011,33(3):570-575
SiO2 samples were implanted by 45 keV Cu ions at a dose of 1 × 1017 /cm2, and subjected to furnace annealing at temperatures ranging from 200 to 600 °C in nitrogen atmosphere. The results indicate that the Cu nanoparticles have been synthesized by Cu ion implantation, and subsequent annealing induces the diffusion and nucleation of nanoparticles partially. The results from XPS measurements show that the Cu0 is the dominate charge state in the implanted and subsequent annealed samples. With increasing annealing temperature, the size and distribution of Cu nanoparticles have been modified gradually. The surface plasmon resonance (SPR) of Cu nanoparticles at 570 nm has been observed by optical transmission spectroscopy. The strongest SPR signal at 400-600 °C indicates that lots of Cu nanoparticles have grown and show good optical properties. Moreover, the luminescence has been investigated in Cu implanted and subsequent annealed samples. Possible luminescence mechanisms, such as radiation induced defects, Cu (ions or atoms) related luminescence centers, etc., have been discussed. 相似文献
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13.
Carbon-doped β-FeSi2 films synthesized by ion implantation is investigated with the aim to fabricate high-quality semiconducting β-FeSi2 layer on silicon substrate. According to our TEM cross-section observations, the carbon-doped films are of better quality than the non-doped ones for their improved uniform film thickness, smooth β/Si interface and high thermal stability. In particular, annealing at 500-700 °C leads to the formation of a flat and continuous β-type silicide layer. Optical absorption measurements show that the carbon doping does not influence the band structure. We further point out that the presence of multiple and incoherent orientation relationships between β and Si, discussed within the framework of the near coincident site lattice theory, is a key factor responsible for the difficulty in obtaining high-quality epitaxial β films. 相似文献
14.
Thermal annealing effects on Zn+ ion-implanted silica glass (a-SiO2) have been studied in order to control void formation. Void formation in a-SiO2 with Zn+ ion implantation and subsequent oxidation has been observed using transmission electron microscopy (TEM). Zn+ ions of 60 keV were implanted into a-SiO2 to a fluence of 1.0 × 1017 ions/cm2. After the implantation, thermal annealing at 600 or 700 °C for 1 h in oxygen gas was conducted. In as-implanted state, metal Zn nanoparticles (NPs) of 10-15 nm in diameter are formed in the depth region around the projected range. The size of the Zn nanoparticles increases after the annealing at 600 °C in oxygen gas. Annealing in oxygen gas at 700 °C for 1 h caused two processes: (1) the migration of Zn atoms which formed Zn NPs in as-implanted state to the surface of the a-SiO2 substrate and (2) the transformation to the oxide phase on the substrate. The transportation of Zn NPs to the surface leaves voids of 10-25 nm in diameter inside the a-SiO2. These results indicate that the oxidation at 700 °C for 1 h causes the migration of Zn atoms to the surface without diffusion and recombination of vacancies which form the voids. 相似文献
15.
J. Gazecki J. M. Kubica M. Zamora G. K. Reeves C. M. Johnson M. C. Ridgway 《Thin solid films》1999,340(1-2):233-236
Planar optical waveguides formed by Si ion implantation into PECVD SiO2 have been characterized by the dark mode spectroscopy method at a wavelength of 0.6328 μm. The measured effective index values of the guided modes have been used to investigate the optical properties of the core layers of the waveguides after different pre-implantation treatments. It was found that annealing the specimens before implantation, affected both the refractive index and thickness of the core layers. In the annealed specimens a thicker core layer and a larger relative refractive index difference between the core and the buffer layer resulted. 相似文献
16.
Metal nanocluster composite glass prepared by 250 keV Au ions into silica with dose of 1 × 1017 ions/cm2 has been studied. The microstructural properties of the nanoclusters are characterized by optical absorption spectra and transmission electron microscopy (TEM). Third-order optical properties of the nanoclusters are studied by the Z-scan technique under 1064 nm and 532 nm excitations. The nonlinear refraction index, nonlinear absorption coefficient, and the real and imaginary parts of the third-order nonlinear susceptibility are deduced. The results of the investigation of nonlinear refraction using the off-axis Z-scan configuration are presented and the mechanisms responsible for the nonlinear response are discussed. The third-order nonlinear susceptibility χ(3) of this kind of sample was determined to be 1.6 × 10−7 esu at 532 nm and 1.3 × 10−7 esu at 1064 nm. 相似文献
17.
A. L. Stepanov 《Technical Physics Letters》2002,28(10):864-867
Sapphire-based composite layers implanted with 40-keV Cu+ ions to a total dose of 1.0×1017 cm−2 at an ion beam current density varied from 2.5 to 10 μA/cm2 were studied using Rutherford backscattering and optical reflectance methods. The appearance of optical plasma resonance lines in the reflectance spectra indicates that ion implantation allows copper nanoparticles to be synthesized in the subsurface region of the dielectric crystal studied. 相似文献
18.
Metallic V nanoparticles (NPs) were formed in silica glass by implantation with V+ ions of 60 keV to a fluence of 1.0 × 1017 ions/cm2. Annealing in oxygen gas at 800 °C transformed the metallic NPs to oxide NPs. While the mean diameter of the metal V NPs was 8.4 nm in the as-implanted state, the diameters steeply increased during oxidation, with some exceeding 100 nm. Since at least 15 different composition phases, such as V2O3, V3O7, V6O13, V9O17, etc., are known for vanadium oxides, identification of the oxide phase of the NPs was not easy. X-ray diffraction (XRD) was not a powerful tool for phase identification of the NPs, because the diffraction peaks were broad due to the nanometric sizes of the particles and readily shift due to stress effects. The temperature dependence of the optical absorption spectrum was measured. The observed spectra were almost unchanged between 3.3 and 370 K. Combining the spectral result and the XRD results, the candidates were narrowed down to three phases, V2O5, V4O9, and V7O13, from the 15 candidates. Among the three, the V2O5 phase is the most probable because the absorption spectrum and the oxygen partial pressure for its formation were both consistent. 相似文献
19.
A. L. Stepanov C. Marques E. Alves R. C. da Silva M. R. Silva R. A. Ganeev A. I. Ryasnyansky T. Usmanov 《Technical Physics Letters》2005,31(8):702-705
Single crystal Al2O3 substrates have been implanted with 160-keV Au+ to a dose of 0.6 × 1017 or 1.0 × 1017 cm−2, with a postimplantation annealing for 1 h at 800°C in air. The obtained composite layers were studied by the method of linear
optical reflection; the nonlinear optical characteristics were determined by the RZ-scan technique using picosecond radiation pulses of an Nd:YAG laser operating at 1064 nm. The appearance of a characteristic
surface optical plasmon resonance band in the linear reflection spectra was indicative of the formation of gold nanoparticles
in a subsurface layer of ion-irradiated Al2O3. It is shown that the synthesized particles are responsible for the observed manifestations of nonlinear refraction. The
composite layers were characterized by the nonlinear refractive index (n
2) and the real part of the third-order nonlinear susceptibility (Reϰ (3)). 相似文献
20.
Nitrogen ions were implanted into melt-grown ZnO (0001) substrates and subsequently annealed at 800 °C under an oxygen ambient. The photoluminescence spectrum of N+-implanted ZnO excited by a He-Cd laser exhibited donor-acceptor pair (DAP) transition emission at 385 nm with a full width at half maximum of 30 nm at 10 K. The DAP emission is associated with the acceptor energy of nitrogen in ZnO, calculated to be 170 meV. Defect-related red emission at about 610 nm observed in N+-implanted ZnO was due to the residual damage from the implantation step because it was also observed in Ar+-implanted ZnO but not in un-implanted ZnO annealed at 800 °C under the same oxygen ambient. 相似文献