共查询到20条相似文献,搜索用时 31 毫秒
1.
Jingwei Chen Quan Ren Xinqiang Wang Tingbin Li Hongliang Yang Jingnan Zhang Guochao Li 《Optik》2012,123(19):1761-1764
A novel organometallic compound, ethyltriphenylphosphonium bis(2-thioxo-1,3-dithiole-4,5-dithiolato)aurate (III), abbreviated as TPEPADT, was synthesized. The TPEPADT doped poly(methyl methacrylate) (PMMA) thin film with a mass fraction of 1% (1 wt.%) was prepared by using a spin-coating method. The third-order nonlinear optical properties of TPEPADT in acetonitrile solution and TPEPADT-doped PMMA thin film were investigated by using the laser Z-scan technique at the wavelength 1064 nm with laser duration of 20 ps. The linear refractive index of the polymer thin film was also studied. The Z-scan curves revealed that both TPEPADT in acetonitrile solution and the polymer thin film possessed negative nonlinear refraction, exhibiting a self-defocusing effect and nonlinear absorption was negligible under the experimental conditions used. The nonlinear refractive index was calculated to be ?1.9 × 10?18 m2/W for TPEPADT in acetonitrile solution and ?8.9 × 10?15 m2/W for the polymer thin film. These results suggest that TPEPADT have potential for the application of all-optical switching devices. 相似文献
2.
《Current Applied Physics》2009,9(2):467-471
Cadmium stannate thin films were prepared by spray pyrolysis technique using cadmium acetate and tin(II) chloride precursors at substrate temperatures 450 °C and 500 °C. XRD pattern confirms the formation of orthorhombic (1 1 1) cadmium stannate phase for the film prepared at substrate temperature of 500 °C, whereas, films prepared at 450 °C are amorphous. Film formation does not occur at substrate temperature from 300 to 375 °C. SEM images reveal that the surface of the prepared Cd2SnO4 film is smooth. The average optical transmittance of ∼86% is obtained for the film prepared at substrate temperature of 500 °C with the film thickness of 400 nm. The optical band gap value of the films varies from 2.7 to 2.94 eV. The film prepared at 500 °C shows a minimum resistivity of 35.6 × 10−4 Ω cm. 相似文献
3.
Thin films of tungsten phosphate glasses were deposited on a Pd substrate by a pulsed laser deposition method and the flux of hydrogen passed thorough the glass film was measured with a conventional gas permeation technique in the temperature range 300–500 °C. The glass film deposited at low oxygen pressure was inappropriate for hydrogen permeation because of reduction of W ions due to oxygen deficiency. The membrane used in the hydrogen permeation experiment was a 3-layered membrane and consisted of Pd film (~ 20 nm), the glass film (≤ 300 nm) and the Pd substrate (250 µm). When the pressure difference of hydrogen and thickness of the glass layer were respectively 0.2 MPa and ~ 100 nm, the permeation rate through the membrane was 2.0 × 10? 6 mol cm? 2 s? 1 at 500 °C. It was confirmed that the protonic and electronic mixed conducting glass thin film show high hydrogen permeation rate. 相似文献
4.
《Current Applied Physics》2005,5(5):475-479
The surface of ultra high molecular weight polyethylene (UHMWPE) was exposed to γ-ray for improving bonding strength to polymethylmethacrylate (PMMA) bone cement. Two types of irradiation methods, pre-irradiation and syn-irradiation, were engaged in this study. The intensity of irradiation was 5–30 kGy for pre-irradiation, and 1–3 kGy for syn-irradiation. The grafting process was performed in a glass ampule filled with methanol, MMA monomer (60 v%), FeSO4 · 7H2O (1.5 × 10−4 M) and H2SO4 (0.1 M). The graft rate of each specimen was measured with time variation. The grafting effect of the acrylates on to the UHMWPE surface was investigated by mechanical test for bonding strength. Pre-irradiation method showed thinner coverage PMMA graft on the surface of the UHMWPE and higher bonding strength than syn-irradiation method. The interfacial bonding strength between UHMWPE and PMMA bone cement was considerably improved by γ-ray irradiation method. For medical application, the pre-irradiation method might be recommended, because the PMMA could be grafted as optimized thickness to the UHMWPE surface. 相似文献
5.
T. Hasegawa S. Munakata S. Imanishi Y. Kakefuda K. Edamoto K. Ozawa 《Surface science》2012,606(3-4):414-419
Titanium oxide films grown on Mo(100) have been investigated by low-energy electron diffraction (LEED) and soft X-ray photoelectron spectroscopy (PES). The film was grown by Ti deposition on Mo(100) and subsequent oxidation of the film by 12 L of O2 exposure at room temperature. As the film was annealed at 700–1000 °C, the film in which the Ti atoms were in a Ti3+ oxidation state was formed. As the film was annealed at 1100–1500 °C, the oxidation state of Ti in the film was converted to Ti2+. The valence electronic structure of the film was measured under the condition that the emission from the Mo substrate was minimized due to a Cooper minimum of the Mo 4 d photoionization cross sections (hν = 100 eV). It was found that the Ti 3 d band in normal-emission spectra was increased in intensity when the film was annealed at 1100–1500 °C. As the film was annealed at 1300 °C for 10 s and 20 s, the film-covered Mo(100) gave (2 × 2) and (4 × 1) LEED patterns, respectively. The two-dimensional band structure of the (2 × 2) system was investigated by angle-resolved PES, and it was found that the film with a (1 × 1) periodicity with respect to the Mo(100) substrate existed in the (2 × 2) system. 相似文献
6.
《Solid State Ionics》2009,180(40):1667-1671
Gd0.5Sr0.5CoO3 (GSCO) film has been fabricated by pulsed laser deposition (PLD) to be used as the cathode of the solid oxide fuel cell (SOFC). The GSCO thin film obtained has a columnar crystalline structure so that it will have a high permeation property. The PLD technique has been found suitable for growing a film of complex composition because of its good control of stoichiometry and thus for fabricating a GSCO film used as the cathode of the SOFC. The GSCO film has been studied for porosity electrical conductivity and power density. The GSCO film grown at a substrate temperature of 1100 K and oxygen gas pressure of 100 Pa has high electrical conductivity which is 820 S cm− 1 at 973 K with post annealing at a rather low temperature (1000 K). This value is higher than that of the GSCO film prepared by RF-sputtering with post annealing at a higher temperature (1273 K). 相似文献
7.
High speed patterning of a 30 nm thick Aluminium thin film on a flexible Polyethylene Terephthalate substrate was demonstrated with the aid of Computer Generated Holograms (CGH׳s) applied to a phase only Spatial Light Modulator. Low fluence picosecond laser pulses minimise thermal damage to the sensitive substrate and thus clean, single and multi-beam, front side thin film removal is achieved with good edge quality. Interestingly, rear side ablation shows significant Al film delamination. Measured front and rear side ablation thresholds were Fth=0.20±0.01 J cm−2 and Fth=0.15±0.01 J cm−2 respectively. With laser repetition rate of 200 kHz and 8 diffractive spots, a film removal rate of R>0.5 cm2 s−1 was demonstrated during patterning with a fixed CGH and 5 W average laser power. The effective laser repetition rate was feff~1.3 MHz. The application of 30 stored CGH׳s switching up to 10 Hz was also synchronised with motion control, allowing dynamic large area multi-beam patterning which however, slows micro-fabrication. 相似文献
8.
《Current Applied Physics》2009,9(1):87-91
The present article demonstrates the use of low-cost electrochemically synthesized hydrophilic and nanocrystalline tin oxide film electrodes at room temperature in dye-sensitized solar cells and electrochemical supercapacitors. A mixed phase of tin instead of single phase composed of uniformly distributed irregular spherical grains in a nanometer regime scale was obtained. Tin oxide film electrode showed efficient photoperformance when subjected to dye-sensitized solar cells. The interfacial and specific capacitances of 118.4 μF/cm2 and 43.07 F/g, respectively, in 0.1 M NaOH electrolyte were confirmed from cyclic-voltammetry measurement. 相似文献
9.
《Current Applied Physics》2009,9(2):510-514
The W film was prepared on 1045 steel by magnetron sputtering, with the thickness of 2 μm, its surface and cross-section morphologies were investigated with SEM, and the phase structure was analyzed with XRD. X-ray stress determinator was utilized to measure its residual stress, and the nano-hardness and elastic modulus of the film were surveyed by nano-indentation tester. The results show that the surface of W film is very compact and smooth; the particles arranged regularly, the granularity of the thin film is about 1 μm. The microcracks, cavities and desquamation were not found in the film and interface, and the bonding between the W film and substrate is well. The XRD results showed that the W film had a body-centered cubic structure, the lattice constant: a = 0.316 nm, the growth preferred orientations are (1 1 0) and (2 2 0). The compressive stress (−169 MPa) was found on the surface. The average nano-hardness and elastic modulus of W film are 15.22 GPa, 176.64 GPa, respectively, and the mechanical properties of W film are well. 相似文献
10.
We investigate selective patterning of ultra-thin 20 nm Indium Tin Oxide (ITO) thin films on glass substrates, using 343, 515, and 1030 nm femtosecond (fs), and 1030 nm picoseconds (ps) laser pulses. An ablative removal mechanism is observed for all wavelengths at both femtosecond and picoseconds time-scales. The absorbed threshold fluence values were determined to be 12.5 mJ cm−2 at 343 nm, 9.68 mJ cm−2 at 515 nm, and 7.50 mJ cm−2 at 1030 nm for femtosecond and 9.14 mJ cm−2 at 1030 nm for picosecond laser exposure. Surface analysis of ablated craters using atomic force microscopy confirms that the selective removal of the film from the glass substrate is dependent on the applied fluence. Film removal is shown to be primarily through ultrafast lattice deformation generated by an electron blast force. The laser absorption and heating process was simulated using a two temperature model (TTM). The predicted surface temperatures confirm that film removal below 1 J cm−2 to be predominately by a non-thermal mechanism. 相似文献
11.
《Current Applied Physics》2009,9(3):673-677
Highly conducting and transparent aluminum doped CdO thin films were deposited using pulsed laser deposition technique. The effect of growth temperature on structural, electrical, and optical properties was studied. It is observed that the film orientation changes from preferred (1 1 1) plane to (2 0 0) plane with increase in growth temperature. The electrical resistivity of the films was found to increase with increase in growth temperature. The low resistivity of 4.3 × 10−5 Ω cm and high transparency (∼85%) was obtained for the film grown at 150 °C. The band gap of the films varies from 2.74 eV to 2.84 eV. 相似文献
12.
《Current Applied Physics》2009,9(1):67-72
The dependence of structural and electrical properties of SnO2 films, prepared using spray pyrolysis technique, on the concentration of fluorine is reported. X-ray diffraction, FTIR and scanning electron microscope (SEM) studies have been performed on SnO2:F (FTO) films coated on glass substrates. Measured values of Hall coefficient and resistivity are reported. The 7.5 m% of F doped film had a resistivity of 15 × 10−4 Ω cm, carrier density of 18.7 × 1019 cm−3 and mobility of 21.86 cm2 V−1 S−1. The NiO film was coated on an FTO substrate and its electrochromic (EC) behavior was studied and the results are reported and discussed in this paper. 相似文献
13.
《Current Applied Physics》2007,7(4):396-399
We have designed and successfully synthesized an alkylated aluminum quinoline derivative, tris(4-tridecyl-8-quinolinolato)aluminum (TDALQ), which could be used as an emitting material for solution-processible OLEDs. The synthesized material was identified by 1H NMR, IR and FAB-mass spectroscopy. To evaluate electroluminescent properties, TDALQ was spin-cast to fabricate thin film as an emitting layer on ITO/PEDOT substrate and LiF/Al double layer was used as electron injection electrode. The EL device showed a green light emission at 509 nm with CIE chromaticity coordinates of (0.31, 0.52). TDALQ made by a spin-coating method showed good film properties in AFM. 相似文献
14.
S.N. Samarin J.F. Williams O.M. Artamonov J. Henk R. Feder 《Surface science》2010,604(21-22):1833-1839
We present joint experimental and theoretical results on the elastic scattering of spin-polarized electrons from an epitaxial Au film on a W(110) substrate in the energy range from 8 eV to 27 eV. A time-of-flight technique with a position-sensitive detector is applied to measure secondary emission spectra for spin-up and spin-down primary electrons in a specular geometry. The spin-asymmetry of coherently scattered electrons is obtained by selecting the diffraction spot on the detector. Regions of large asymmetries – with a maximum of about ?60 % – are identified for electron energies of about 14 eV. Relativistic multiple-scattering calculations produce spin-orbit-induced asymmetries which are in agreement with their experimental counterparts. They further reveal that large asymmetries are associated with high intensities. This offers the possibility of an efficient new spin polarimeter with a figure of merit of about 1.5 · 10?2. 相似文献
15.
John T. Newberg David E. Starr Susumu Yamamoto Sarp Kaya Tom Kendelewicz Erin R. Mysak Soeren Porsgaard Miquel B. Salmeron Gordon E. Brown Anders Nilsson Hendrik Bluhm 《Surface science》2011,605(1-2):89-94
To understand the interaction of water with MgO(100), a detailed quantitative assessment of the interfacial chemistry is necessary. We have used ambient pressure X-ray photoelectron spectroscopy (XPS) to measure molecular (H2O) and dissociative (OH) water adsorption on a 4 monolayer (ML) thick MgO(100)/Ag(100) film under ambient conditions. Since the entire 4 ML metal oxide (Ox) film is probed by XPS, the reaction of the MgO film with water can be quantitatively studied. Using a multilayer model (Model 1) that measures changes in Ox thickness from O 1s (film) and Ag 3d (substrate) spectra, it is shown that the oxide portion of the MgO film becomes thinner upon hydroxylation. A reaction mechanism is postulated in which the top-most layer of MgO converts to Mg(OH)2 upon dissociation of water. Based on this mechanism a second model (Model 2) is developed to calculate Ox and OH thickness changes based on OH/Ox intensity ratios from O 1s spectra measured in situ, with the known initial Ox thickness prior to hydroxylation. Models 1 and 2 are applied to a 0.15 Torr isobar experiment, yielding similar results for H2O, OH and Ox thickness changes as a function of relative humidity. 相似文献
16.
In the present work, a special solid phase epitaxy method has been adapted for the preparation of CoSi2 film. This method includes an epitaxial growth of Co films on Si (1 0 0) substrate, and in situ annealing of the Co/Si films in vacuum. It has been found that at the substrate temperature of 360°C, fcc cobalt film grows epitaxially on the Si (1 0 0) surface. The crystallographic orientation relations between fcc Co film and Si substrate determined from the electron diffraction result are: (0 0 1) Co//(0 0 1) Si, [1 0 0] Co//[1 1 0]Si. Upon annealing at temperatures range from 500 to 600°C, Co film reacts with Si substrate and transforms into CoSi2. The CoSi2 films prepared by this way are characterized by XTEM, XPS and AFM. 相似文献
17.
《Applied Surface Science》2002,185(3-4):298-302
Surface segregation in high-purity Al–100 ppm Pb foil annealed for 4 h at 540 °C was studied mainly by transmission electron microscopy (TEM) observations. TEM–EDX demonstrated that almost of the lead element segregated not to aluminum surface but predominantly to the oxide amorphous film formed just above aluminum surface. The enrichment of lead in the oxide film was about 30 000 fold. 相似文献
18.
The Atomic Force Microscopy (AFM) helps in evaluating parameters like amplitude or height parameters, functional or statistical parameters and spatial parameters which describe the surface topography or the roughness. In this paper, we have evaluated the roughness parameters for the native poly (vinyl alcohol) (PVA), monomer diaminonaphthalene (DAN) doped PVA, and poly (diaminonaphthalene) (PDAN) doped PVA films prepared in different solvents. In addition, distribution of heights, skewness and Kurtosis moments which describe surface asymmetry and flatness properties of a film were also determined. At the same time line profiles, 3D and 2D images of the surface structures at different scanning areas i.e. 5 × 5 μm2 and 10 × 10 μm2 were also investigated. From the roughness analysis and the surface skewness and coefficient of Kurtosis parameters, it was concluded that for PVA film the surface contains more peaks than valleys and the PDAN doped PVA film has more valleys than peaks. It was also found that the PDAN doped PVA film with acetonitrile solvent was used for substrate in electronics applications because the film gives less fractal morphology. Thus, the AFM analysis with different parameters suggested that the PDAN doped PVA films are smooth at the sub-nanometer scale. 相似文献
19.
Lanthanum-modified lead zirconate titanate (Pb0.93La0.07(Zr0.3Ti0.7)0.93O3, PLZT7/30/70) thin films with and without a seeding layer of PbTiO3 (PT) were successfully deposited on indium-doped tin oxide (ITO) coated glass substrate via spin coating in conjunction with a sol–gel process, and a top transparent conducting thin film of SnO2 was also prepared in the same way. The thicknesses of PLZT and PT layers are 0.5 μm and 24 nm, respectively. The retardance of PLZT film was measured by a new heterodyne interferometer and enhanced by application of a seeding layer of PT. The Pockels linear electro-optical coefficient of PLZT film with a PT layer was determined to be 3.17 × 10?9 m/V when the refractive index is considered as 2.505, which is one order larger than 1.4 × 10?10 m/V for PLZT12/40/60 doped with Dy reported in the literature. The root-mean-square (rms) roughness of PLZT thin film with a PT layer (Rrms = 6.867 nm) was larger than that of PLZT film (Rrms = 0.799 nm). From the comparisons, the average transmittance of PLZT film with a PT seeding layer was 77.01%, which was a little smaller than that of PLZT film (around 80.75%). Experimental results imply that the PT seeding layer plays a key role in the increase of retardance value, leading to a higher Pockels coefficient. 相似文献
20.
Yuanqin Xia Yugang Jiang Rongwei Fan Zhiwei Dong Weijiang Zhao Deying Chen G. Umesh 《Optics & Laser Technology》2009,41(6):700-704
The two-photon absorption (TPA) characteristics of PMMA discs doped with three different dyes were studied using an fs-pulsed Ti-Sapphire laser as the pump source, and employing the open-aperture Z-scan technique. TPA cross-sections obtained for PMMA doped with the dyes PM597, DCM and rhodamine 6G–rhodamine B (co-doped) were found to be equal to 24.7, 33.3 and 32.3 GM, respectively (1 GM=10?50 cm4 s phot?1 mol?1). Furthermore, two-photon fluorescence was measured for the samples containing DCM and rhodamine 6G–rhodamine B (co-doped). Compared to the one-photon fluorescence spectrum, the peaks in the two-photon fluorescence spectrum were red shifted and the extent of red shift increased with increasing doping concentration. We have also observed that the red shift in the two-photon fluorescence peak of the samples in the solid form is much larger than that in the solution state. This phenomenon could be explained by a twisted intra-molecular charge transfer model. 相似文献