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1.
R. Ramanauskas L. Gudavičiūtė A. Kaliničenko R. Juškėnas 《Journal of Solid State Electrochemistry》2005,9(12):900-908
The influence of pulse plating parameters on the surface morphology, grain size, lattice imperfection and corrosion properties
of Zn–Ni alloy has been studied. The coatings were electrodeposited in an alkaline cyanide-free solution. AFM was applied
for surface morphology examination, XRD measurements were carried out for phase composition and texture analysis, electron
probe microanalysis was used for alloy chemical composition studies, while electrochemical techniques were applied for corrosion
performance evaluation. The pulse plated Zn–Ni coatings appeared to consist of the γ-Zn21Ni5 phase and the composition of the alloy depended on the plating parameters. The grain size, lattice imperfection and homogeneity
of grain distribution were established to be the main factors determining corrosion behaviour of the coating.
Presented at the 4th Baltic Conference on Electrochemistry, Greifswald, March 13–16, 2005 相似文献
2.
Shan Jin Liliana I. Duarte Guoxing Huang Christian Leinenbach 《Monatshefte für Chemie / Chemical Monthly》2012,33(2):1263-1274
Abstract
Phase equilibria in the Au–Ge–Ni ternary system were studied by means of scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and differential scanning calorimetry. The phase relations in the solid state at 600 °C as well as a vertical section at Au72Ge28–Ni were established. No ternary compound was found at 600 °C. On the basis of the experimental phase equilibria data, a thermodynamic model of the Au–Ge–Ni ternary system was developed using the CALPHAD method. Thermodynamically calculated phase diagrams are shown at 600 °C, in two vertical sections and the liquidus projection. Reasonable agreement between the calculations and the experimental results was achieved. 相似文献3.
Experimental data on the generation and detection of characteristic X-radiation of elements in electron probe microanalysis of dielectric samples in the low vacuum mode without the deposition of conducting coatings are discussed. The main advantage of the considered method of analysis is the stability of the intensity ratio between diagnostic analyte lines in the wide range of currents of the electron probe and gas phase pressure in the chamber in the range 60–130 Pa, sufficient for obtaining undistorted images of the surface of dielectrics. The stability of the intensity ratio ensures obtaining correct data of the quantitative analysis of nonconducting samples without the deposition of conducting coatings. The main features of low-vacuum microanalysis for the range of gas phase pressures used are discussed, which can create additional difficulties in the study. Among such features is a possibility of the manifestation of reflexes of gas-phase elements, significant underestimation of the relative emission intensity from lighter elements in the composition of the studied samples, loss of scanning locality in the analysis of small sites on the sample surface. An example of the correct quantitative elemental analysis of a dielectric surface without the deposition of an electroconductive coating for a number of aluminosilicates is presented. 相似文献
4.
Hybrid organic–inorganic nanocomposite coatings were prepared by copolymerizing tetraethylorthosilicate with ethyltriethoxysilane
with an acid catalysis process. Oxygen sensor coatings were fabricated by doping the hybrid sol with platinum meso-tetra(pentfluorophenyl)
porphyrin. Photophysical properties and oxygen sensitivity of the sensor coatings were studied. The microstructure of the
coatings was examined using optical microscopy and scanning electron microscopy. The effect of sol–gel process conditions
like precursor silane molar ratio, acid concentration and stirring time of the sol on the oxygen sensitivity and surface microstructure
of the sensor coating was studied. Oxygen sensitivity and surface morphology of the coatings were dependent on the sol–gel
process parameters. 相似文献
5.
Electrodeposition of Mg with Zn in acidic sulfate solutions with polyethylene glycol and octadecyl dimethyl benzyl ammonium
chloride as additives was investigated by scanning electron microscopy, X-ray diffraction, and potentiodynamic polarization
techniques. The results show that these two compounds act in a synergetic way to suppress Zn deposition markedly and facilitate
Mg reduction. Zn–0.46%Mg coatings are produced under high cathodic current densities, which have lower corrosion potentials
than Zn coatings and hydrogen evolution in neutral chloride solutions. Magnesium hydroxide may cause current oscillations
at high cathodic polarizations in plating solutions without zinc salts due to its formation and peel-off. An “induced co-deposition”
mechanism is proposed for Zn–Mg alloy electrodeposition. 相似文献
6.
《Spectrochimica Acta Part B: Atomic Spectroscopy》2005,60(11):1381-1391
Electron probe microanalysis (or Scanning electron microscope-energy dispersive X-ray spectrometry) has been studied under grazing-exit conditions. That is, characteristic X-rays are detected at a very small take-off (exit) angle; the technique is known as grazing-exit electron probe microanalysis (GE-EPMA). Fundamental aspects, instrumentation, and characteristics of grazing-exit electron probe X-ray microanalysis method are described here. Since the observation depth decreases as the exit angle decreases, theoretically to a few nanometers, surface analysis is possible in grazing-exit electron probe X-ray microanalysis. Of course, the size of the electron beam is also small—less than 1 μm, enabling localized surface analysis. In the case of total reflection X-ray spectrometry that allows surface analysis, the whole sample surface must be flat. However, the requirement for flatness is not as strict in grazing-exit electron probe X-ray microanalysis. Grazing-exit electron probe X-ray microanalysis measurements can easily be applied using a commercially available electron probe microanalysis (or Scanning electron microscope-energy dispersive X-ray spectrometry) instrument. To change and control the exit angle in grazing-exit electron probe X-ray microanalysis, the inclination of the sample stage or movement of the X-ray detector is all that is required. Theoretically, this study shows that grazing-exit electron probe X-ray microanalysis would be useful in improving the lateral resolution of the sample surface. In addition, the study demonstrates that grazing-exit electron probe X-ray microanalysis can be applied successfully for surface, thin-film, and particle analyses. As an optional method of electron probe microanalysis, grazing-exit electron probe X-ray microanalysis will be useful in expanding the research fields of normal electron probe microanalysis. 相似文献
7.
Preparation and characterization of copper/silver bimetallic nanowires with core‐shell structure
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Core‐shell copper/silver bimetallic nanowires were prepared by replacement reaction with citric acid and polyvinylpyrollidone at room temperature. A uniform silver coating was obtained by strictly controlling the molar ratio of Ag/Cu. The copper/silver composite was characterized by X‐ray diffraction, scanning electron microscopy, electron probe microanalysis and X‐ray photoelectron spectroscopy. Microscopic analysis shows that a well‐copper/silver core‐shell structure was formed. Thermo‐gravimetry and differential thermal analysis to the composite nanowires show that the silver coatings efficiently inhibit the oxidation of Cu. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
8.
D. L. Wang Y. Q. Wu X. Y. Zhong W. Q. Zhang M. C. Li J. N. Shen 《Russian Journal of Electrochemistry》2009,45(3):291-295
The influence of pulse electrodeposition parameters (i.e., current-on time, current-off time and peak current density) on
the grain size and orientation of zinc deposits was investigated in acidic sulfate electrolyte. The scanning electron microscopy
(SEM) and X-ray diffraction (XRD) analyses indicate that the pulse parameters play an important role in the grain refinement
of nanocrystalline zinc coatings. As varying peak current density (1–2 A/cm2), current-on time (1–6 ms) and current-off time (4–18 ms), nanocrystalline zinc coatings are produced in the grain range
60 to 35 nm. The pulse parameters have a slight influence on the orientation of nanocrystalline zinc coatings.
Published in Russian in Elektrokhimiya, 2009, vol. 45, No. 3, pp. 310–315.
The article is published in the original. 相似文献
9.
Väino Sammelselg Eero Rauhala Kai Arstila Alex Zakharov Jaan Aarik Arvo Kikas Juhan Karlis Aivar Tarre Anni Seppälä Jelena Asari Indrek Martinson 《Mikrochimica acta》2002,139(1-4):165-169
Titanium oxide and zirconium oxide thin films deposited on silicon substrates were characterised using electron probe microanalysis
(EPMA), Rutherford backscattering spectroscopy (RBS), time-of-flight elastic recoil detection analysis (TOF-ERDA) and scanning
photoelectron microscopy (SPEM). The composition and mass thickness of the films were determined and the results of different
methods compared. It was revealed that the synchrotron radiation used for SPEM studies caused considerable modification of
zirconia films grown at low temperatures. 相似文献
10.
Allan Hallik Ants Alumaa Väino Sammelselg Jüri Tamm 《Journal of Solid State Electrochemistry》2001,5(4):265-273
Polypyrrole/dodecylsulfate (PPy/DDS) films were synthesized in aqueous and ethanolic solutions and investigated in aqueous,
ethanolic, methanolic and acetonitrile solutions by cyclic voltammetry (CV). The amounts of anions and cations in the films
before and after electrochemical treatment were determined by electron probe microanalysis (EPMA); the film morphology was
studied by scanning electron microscopy (SEM). The results prove that the mobility of bulky DDS– ions in PPy increases in the order: water<acetonitrile<ethanol<methanol. It was found that dopant DDS– ions can be easily removed from PPy matrix swollen in alcohols or acetonitrile by electrochemical reduction or by soaking
in electrolyte solutions of these solvents. The influence of electrochemical treatment on the change of doping level in aqueous
solution is essentially less and depends on the cations in the test solution. Although the electroneutrality of PPy/DDS films
during redox cycling is realized mainly by movement of the cations in aqueous solution and by movement of the anions in organic
solvents, nevertheless the participation of anions in aqueous and cations in organic solvents is also established. The redox
properties of PPy/DDS are more dependent on the solvent of the test solutions than of the synthesis solutions.
Electronic Publication 相似文献
11.
Norbert Lesch Anke Aretz Markus Pidun Silvia Richter Peter Karduck 《Mikrochimica acta》2000,132(2-4):377-382
A common problem in depth profile measurement is the calibration of the depth scale. The new technique of sputter assisted
electron probe microanalysis offers the possibility of calculating the composition as well as the depth scale solely from
the acquired X-ray intensity data without further information, e.g. sputter rates. To achieve a depth resolution that is smaller
than the depth of information of the electron probe, i.e. 0.1–1 μm, special deconvolution algorithms must be applied to the
acquired data.
To assess the capabilities of this new technique it was applied to a Ti/Al/Ti multilayer on Si under different measurement
conditions. Quantitative depth profiles were obtained by application of a deconvolution algorithm based on maximum entropy
analysis. By comparison of these profiles with AES depth profiles and AFM roughness measurements, it was shown that the limiting
factor to the achievable depth resolution is the occurrence of surface roughening induced by the sputtering process rather
than the relatively large depth of information of the electron probe.
We conclude that for certain applications sputter-assisted EPMA can be regarded as a valid depth profiling technique with
a depth resolution in the nm range. 相似文献
12.
Kouichi Tsuji Zoya Spolnik Kazuaki Wagatsuma Rik Nullens RenéE. Van Grieken 《Mikrochimica acta》2000,132(2-4):357-360
In conventional electron probe microanalysis (EPMA), the electron-induced X-rays are measured at large take-off angles of
about 45°. In the grazing exit EPMA (GE-EPMA) method, they are measured at small angles (< 1°). X-rays emitted from deep positions
can not be detected at grazing exit angles due to refraction effects at sample-vacuum interface; therefore, it is possible
to measure X-rays emitted only from near the surface with a low background. GE-EPMA is especially suitable for the analysis
of particles deposited on a flat sample carrier. The detection limits of GE-EPMA were investigated for artificial particles
(Al2O3, Fe2O3 and PbO2 , particle sizes: 1 ∼ 18 μm) deposited on flat sample carriers of Au thin films–Si wafers. The detection limits improved
with decreasing exit angle. The detection limits for characteristic X-rays at an exit angle of approximately 1.1° were 2–4
times lower than at 45°. A minimum detection limit of ca. 0.1% was obtained for Al in small particles. 相似文献
13.
K. B. Kalmykov N. L. Zvereva S. F. Dunaev N. V. Kazennov E. V. Tat’yanin G. V. Semernin N. E. Dmitrieva Yu. V. Balykova 《Moscow University Chemistry Bulletin》2009,64(2):99-103
The phase equilibria in the Al-Cu-Fe system at 853 K in the aluminum enriched region are studied using the methods of scanning and transmission electron microscopy, X-ray phase analysis, and electron probe microanalysis. An isothermal cross section of the system is constructed. Crystal lattice parameters of the phases based on binary and ternary compounds are determined. Approximant phases are not found to form in the quasicrystalline i-phase region. 相似文献
14.
Monochrome coloured glass beads of the Merovingians (5th–7th cent. AD) have been examined by different analytical methods. The elemental composition of a large number of mostly unprepared
beads have been measured non-destructively by X-ray fluorescence analysis. After subtracting the content of the colouring
oxides of the glass beads and normalising the residual values to 100% an identical soda-lime-glass matrix was obtained. X-ray
diffraction was used for the identification of the crystalline colouring and opacifying pigments (SnO2, Cu, Cu2O, PbSnO3), and scanning electron microscopy as well as electron probe microanalysis were applied to study the microstructure and the
composition of white, brown, green, orange and yellow coloured glass beads. Oxidised metals, alloys (lead, copper, bronze,
brass and mixtures of them) and iron smelting slag have been identified as raw materials to colour the soda-lime-glass. 相似文献
15.
Maria Ochsenkühn-Petropoulou Rachel Argyropoulou Petros Tarantilis Nikos Deftereos Evagelos Kokkinos Klaus-Michael Ochsenkühn George Parissakis 《Mikrochimica acta》2001,136(3-4):153-158
YBa2Cu3O
7−x
(x = 0.1–0.2) compounds (YBCO) were produced by the oxalate coprecipitation and the solid state reaction methods. The powders
obtained were used for the production of YBCO superconducting coatings on Pt/Si wafers, by the electrophoretic deposition
technique. The optimum process conditions for the production of both powders and coatings were found by using a combination
of modern analytical techniques. The thermal treatment of the samples was followed by thermogravimetry (TG) and differential
scanning calorimetry (DSC). The optimization and characterization of the superconducting properties of the powders and coatings
were achieved by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), optical microscopy, magnetic susceptibility
and electrical resistivity measurements. 相似文献
16.
The potentials of six approximation functions described in the literature and used to simulate bremsstrahlung X-radiation in electron probe microanalysis are analyzed within a uniform approach. An algorithm based on the use of wave spectra is proposed for determining the parameters of the functions. It is found that the calculated values of some parameters of approximation functions considerably differ from those presented by the authors of the functions. It is found that the quality of approximating bremsstrahlung X-radiation is strongly affected by the method of calculating the average atomic number of the sample and the corrections for matrix effects. In the wavelength range 0.1 ≤ λ ≤ 1.2 nm for atomic numbers 10 ≤ Z ≤ 83 and accelerating voltages 15 ≤ E 0 ≤ 25 kV, the best function ensures background estimation with a relative standard deviation of 3–6%, which is comparable with the relative standard deviation of the direct background measurement in routine electron probe microanalysis. The use of the calculation method of the background account at λ > 1.2 nm is complicated because of the significant uncertainty of the absorption factor in the long-wavelength region for the majority of elements. 相似文献
17.
M. S. Vasil’eva V. S. Rudnev A. Yu. Ustinov V. G. Kuryavyi O. E. Sklyarenko N. B. Kondrikov 《Russian Journal of Inorganic Chemistry》2009,54(11):1708-1712
We have studied the composition and structure of films 20–30 μm thick prepared by plasmaassisted electrochemical oxidation
(PEO) and additionally modified by impregnation in aqueous solutions of nickel and copper nitrates and then annealed. The
investigative tools used were powder X-ray diffraction, electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy
(XPS), and atomic force microscopy. Unmodified film/titanium composites have a certain catalytic activity in CO oxidation
to CO2 at temperatures above 300°C; for modified layers, these temperatures are noticeably higher. Modification influences the surface
structure, relief, and elemental composition. Relations between the composition and catalytic properties of the oxide layers
are discussed. 相似文献
18.
Zhen Wei Zheng Liu Rongrong Jiang Chaoqing Bian Tao Huang Aishui Yu 《Journal of Solid State Electrochemistry》2010,14(6):1045-1050
TiO2 array film fabricated by potentiostatic anodization of titanium is characterized by X-ray diffraction (XRD), scanning electron
microscopy (SEM), and charge–discharge measurements. The XRD results indicated that the TiO2 array is amorphous, and after calcination at 500 °C, it has the anatase form. The pore size and wall thickness of TiO2 nanotube arrays synthesized at different anodization voltages are highly dependent on the applied voltage. The electrochemical
performance of the prepared TiO2 nanotube array as an electrode material for lithium batteries was evaluated by galvanostatic charge–discharge measurement.
The sample prepared at 20 V shows good cyclability but low discharge capacity of 180 mA h cm−3, while the sample prepared at 80 V has the highest discharge capacity of 340 mA h cm−3. 相似文献
19.
Itani H Duchoslav J Arndt M Steck T Gerdenitsch J Faderl J Preis K Winkler W Stifter D 《Analytical and bioanalytical chemistry》2012,403(3):663-673
Zn–Cr alloyed coatings electrochemically deposited are of high interest for leading steel manufacturing companies because
of their novel properties and high corrosion resistance compared with conventional Zn coatings on steel. For tuning and optimizing
the properties of the electrodeposited Zn–Cr coatings, a broad range of the deposition conditions must be studied. For this
reason, two different types of material were investigated in this study, one with a low electrolyte temperature and one with
an elevated electrolyte pH, compared with the standard values. Because different corrosion performance and delamination behaviour
of the layers were observed for the two types, advanced surface analysis was conducted to understand the origin of this behaviour
and to discover differences in the formation of the coatings. The topmost surface, the shallow subsurface region, and the
whole bulk down to the coating–steel interface surface were analysed in detail by X-ray photoelectron spectroscopy (XPS) and
high-resolution scanning Auger electron spectroscopy to determine the elemental and the chemical composition. For better understanding
of the resulting layer structure, multiple reference samples and materials were measured and their Auger and XPS spectra were
fitted to the experimental data. The results showed that one coating type is composed of metallic Zn and Cr, with oxide residing
only on the surface and interface, whereas the other type contains significant amounts of Zn and Cr oxides throughout the
whole coating thickness. 相似文献
20.
V. P. Korzhov 《Russian Journal of General Chemistry》2010,80(6):1097-1102
By an example of porous metal tubes and thin plates prepared from the stainless steel powder a simple method is described
of preparation of porous metallic substrates for superconducting coatings. The tubes outer diameter is 12 mm, length up to
300 mm, wall thickness about ∼1.5 mm. The plate size is 85×85 mm, thickness 1 mm. We used the classic method of powder metallurgy,
without any fillers. After sintering, the tube had a density 2.5–3.4 g cm−3 and open porosity 55–65%. The microstructure of the tubes and plates surfaces and breaks was studied using scanning electron
microscopy. The porous tubes were prepared also from powdered copper, nickel, titanium, and chromium, as well as from mixtures
of stainless steel and copper, nickel and pseudoalloy Cu(30%)-Cr. The first coatings with superconducting compound MgB2 were prepared. 相似文献