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991.
992.
Abdollah Sarani Nathalie De GeyterRino Morent Christophe Leys 《Applied Surface Science》2011,257(20):8737-8741
In this paper, an atmospheric pressure plasma jet sustained in pure argon and an argon/water vapour mixture has been used to modify the surface of polypropylene (PP) films. The gas temperature of the plasma jet was found to be 625 K in an active zone between the electrodes and was found to increase in the afterglow. Based on these results, the PP films are placed as close as possible to the edge of the capillary in order to avoid thermal damage to the polymer. XPS results on the untreated and modified PP samples revealed incorporation of a significant amount of oxygen on the polymer surface, however, this oxygen inclusion is more pronounced for the argon/water vapour jet due to the higher radicals density in the jet afterglow. One can therefore conclude that adding water vapour to an argon plasma jet can be a convenient way to increase the efficiency of plasma surface modification. 相似文献
993.
J.W. Chiou S.Y. ChangW.H. Huang Y.T. ChenC.W. Hsu Y.M. HuJ.M. Chen C.-H. ChenK. Kumar J.-H. Guo 《Applied Surface Science》2011,257(11):4863-4866
X-ray absorption near-edge structure (XANES), X-ray emission spectroscopy (XES), and X-ray photoemission spectroscopy (XPS) were used to characterize the Cr secondary oxide phases in ZnO films that had been prepared using a co-sputtering method. Analysis of the Cr L3,2-edge XANES spectra reveals that the intensity of white-line features decreases subtly as the sputtering power increases, indicating that the occupation of Cr 3d orbitals increases with Cr concentration in (Zn, Cr)O films. The O K-edge spectra show that the intensity of XANES features of (Zn, Cr)O films is lower than those of ZnO film, suggesting enhanced occupation of O 2p-derived states through O 2p-Cr 3d hybridization. The XES and XPS spectra indicate that the line shapes in the valence band of (Zn, Cr)O films are quite different from those of ZnO and that the Cr2O3 phase dominates the spinel structure of (Zn, Cr)O films increasingly as the Cr sputtering power is increased. Over all results suggest that the non-ferromagnetic behavior of (Zn, Cr)O films can be attributed to the dominant presence of Cr2O3, whereas the bulk comprise phase segregations of Cr2O3 and/or ZnCr2O4, which results them the most stable TM-doped ZnO material against etching. 相似文献
994.
Udai B. Singh D.C. AgarwalS.A. Khan Manish KumarA. Tripathi R. SinghalB.K. Panigrahi D.K. Avasthi 《Applied Surface Science》2011,258(4):1464-1469
Hydrophilic Ag nanostructures were synthesized by physical vapour deposition of 5 nm Ag thin films followed by irradiation with 1.5 keV Ar atoms. Optical absorbance measurements show a characteristic surface plasmon resonance absorption band in visible region. A blue-shift in absorbance from 532 to 450 nm is observed with increasing fluence from 1 × 1016 to 3 × 1016 atoms/cm2. Atomic force microscopy was performed for the pristine and irradiated samples to study the surface morphology. The atom beam irradiation induced sputtering and surface diffusion lead to the formation of plasmonic surface. Rutherford backscattering spectroscopy of the pristine and irradiated film indicates that metal content in the film decreases with ion fluence, which is attributed to the sputtering of Ag by Ar atoms. The contact angle measurement demonstrates the possibility of engineering the hydrophilicity by atom beam irradiation. 相似文献
995.
Jingkai YangWenchang Liu Lizhong DongYuanxun Li Chuan LiHongli Zhao 《Applied Surface Science》2011,257(24):10499-10502
Fluorine-doped tin oxide films (SnO2:F, FTO) were deposited by atmosphere pressure chemical vapor deposition (APCVD) on Na-Ca-Si glass coated with a diffusion barrier layer of SiOxCy. The effects of post-heating time at 700 °C on the structural and electrical properties of SnO2:F films were investigated. The results showed that SnO2:F films were polycrystalline with tetragonal SnO2 structure, SnO phase was present in SnO2 film, and abnormal grain growth was observed. The element distribution in the film depth was measured with X-ray photoelectron spectroscopy (XPS) and revealed that when the heating time increased from 202 s to 262 s, the oxygen content in the surface increased from 78.63% to 83.38%. The resistivity increased from 3.13 × 10−4 for as-deposited films to 4.73 × 10−4 Ω cm when post-heated for 262 s. Hall mobility is limited by the ionized impurity scattering rather than the grain boundary scattering. 相似文献
996.
Vinit K. MittalSantanu Bera S.V. NarasimhanS. Velmurugan 《Applied Surface Science》2011,258(4):1525-1530
Sorption of Sb(III) on carbon steel surface in aqueous medium (pH 2.8) in presence of different oxyanions like molybdate and selenite has been studied. It is observed that the presence of molybdate or selenite in solution reduced Sb(III) adsorption and surface precipitation to a great extent. The solution at different stages of the adsorption experiment has been analyzed by inductively coupled plasma-atomic emission spectroscopy technique. X-ray diffraction and X-ray photoelectron spectroscopy (XPS) techniques have been used to characterize the precipitate layer and the adsorbed layer. A detailed analysis of the XPS data reveals the mechanism involved in the two cases. 相似文献
997.
Interactions between CdSe/CdS quantum dots and DNA through spectroscopic and electrochemical methods
Qisui Wang Lu YangTingting Fang Shuang WuPeng Liu Xinmin Min Xi Li 《Applied Surface Science》2011,257(23):9747-9751
The interaction of CdSe/CdS quantum dots (QDs) with Herring sperm-DNA (hs-DNA) has been studied by UV-vis spectroscopy and electrochemical method. Cu(phen)22+/1+ (phen = 1, 10-phenanthroline) was used as an indicator for electroactive dsDNA or ssDNA. The apparent association constant has been deduced (4.94 × 103 M−1 and 2.39 × 102 M−1) from the absorption spectral changes of the dsDNA-QDs and ssDNA-QDs. The results of dissociation method suggest that Cu(phen)22+/1+ is more easily dissociated from dsDNA or ssDNA modified gold electrode (dsDNA/Au or dsDNA/Au) in presence of QDs. The dissociation rate constant (k) of Cu(phen)22+/1+ on dsDNA/Au is 4.48 times higher than that in absence of QDs, while k is 2.34 times higher than that in absence of QDs on ssDNA/Au in Tris buffer with low ionic strength (pH 7.0, 0.5 mM NaCl). The results illuminate that hs-DNA has high affinity for QDs due to electrostatic force, hydrogen bonds, and van der Waals interactions, and the binding force of QDs with dsDNA is stronger than ssDNA. 相似文献
998.
In present investigation MnO2 thin films have been prepared by potentiodynamic (PD), potentiostatic (PS) and galvanostatic (GS) modes of electrodeposition. The effects of different modes on structural, surface morphological and supercapacitive properties of MnO2 thin films have been investigated. Formation of amorphous phase of MnO2 by all three modes is confirmed from X-ray diffraction (XRD) patterns. Significant change in the surface morphologies of MnO2 thin films due to different modes has been observed. The supercapacitive properties of MnO2 thin films have been studied in 1 M Na2SO4 electrolyte. The maximum supercapacitance obtained for potentiodynamic, potentiostatic and galvanostatic modes is 237, 196 and 184 F g−1, respectively. Additionally charge-discharge and impedance of MnO2 thin films have been investigated. 相似文献
999.
Carbon nitride films by RF plasma assisted PLD: Spectroscopic and electronic analysis 总被引:1,自引:0,他引:1
E. Cappelli S. OrlandoD.M. Trucchi A. BellucciV. Valentini A. MezziS. Kaciulis 《Applied Surface Science》2011,257(12):5175-5180
Carbon nitride (CNx) thin films have been grown on Si 〈1 0 0〉 by 193 nm ArF ns pulsed laser ablation of a pure graphite target in a low pressure atmosphere of a RF generated N2 plasma and compared with samples grown by PLD in pure nitrogen atmosphere. Composition, structure and bonding of the deposited materials have been evaluated by X-ray photoelectron spectroscopy (XPS), and Raman scattering. Significant chemical and micro-structural changes have been registered, associated to different nitrogen incorporation in the two types of films analyzed. The intensity of the reactive activated species is, indeed, increased by the presence of the bias confined RF plasma, as compared to the bare nitrogen atmosphere, thus resulting in a different nitrogen uptake in the growing films. The process has been also investigated by some preliminary optical emission studies of the carbon plume expanding in the nitrogen atmosphere. Optical emission spectroscopy reveals the presence of many excited species like C+ ions, C atoms, C2, N2; and CN radicals, and N2+ molecular ions, whose relative intensity appears to be increased in the presence of the RF plasma. The films were also characterised for electrical properties by the “four-probe-test method” determining sheet resistivity and correlating surface conductivity with chemical composition. 相似文献
1000.
采用传统的固相反应法,在1400–1500 ℃下烧结,制备得到Al2O3-Y2O3-ZrO2三相复合陶瓷.样品的结构、形貌和电性能分别用X射线衍射(XRD)、扫描电子显微镜(SEM)及介电谱表征.XRD表明此三相复合体系无其他杂相,加入Y2O3及ZrO2后使得Al2O3成瓷温度降低;SEM表明此体系晶粒直径为200–500 nm,并且样品随烧结温度的升高而变得更加致密,晶界更加清晰;介电损耗谱中出现峰值弛豫现象,根据Cole-Cole复阻抗谱得出其为非德拜弛豫.
关键词:
2O3-Y2O3-ZrO2三相陶瓷')" href="#">Al2O3-Y2O3-ZrO2三相陶瓷
介电弛豫
阻抗谱
热导率 相似文献