共查询到20条相似文献,搜索用时 15 毫秒
1.
A highly stable plating bath for the electrodeposition of Fe–Pd nanowires into nanoporous alumina templates has been developed. Complexing of both metal ions and exchanging Fe2+ by Fe3+ avoid chemical reduction of Pd ions and, therefore, undesirable deposition. By using a pulse potential mode and appropriate adjustment of deposition potentials homogeneously filled templates without surface deposits and nanowires close to the desired composition of Fe70Pd30 have been achieved. These alloy nanowires represent a key step towards nanoactuators based on magnetic shape memory alloys. 相似文献
2.
Steady-state potentials of Ir, Ru, and glassy carbon are measured at 500–700°C in eutectic NaCl-KCl-CsCl melts containing
a mixture of Ir and Ru chlorides. The Ir and Ru steady-state potentials are more positive than their equilibrium values, due
to the alloying in the metal surface layer. In the cathodic deposition of alloys, depolarization is observed. Before the limiting
diffusion current, Ir-Ru alloys (solid solutions) are plated as compact layers; at higher current densities, the deposit is
a powdered dendritic mixture of individual Ir and Ru crystals, rather than the alloy 相似文献
3.
Milin Zhang Yusheng Yang Wei Han Mei Li Ke Ye Yi Sun Yongde Yan 《Journal of Solid State Electrochemistry》2013,17(10):2671-2678
In the work, Gibbs energy showed that MgCl2 can chloridize Dy2O3 and release Dy(III) ions in the LiCl–KCl–MgCl2–Dy2O3 melts. Dy(III) ions were observed by cyclic voltammetry, square wave voltammetry in melts. X-ray diffraction (XRD) pattern of melts indicated that Dy2O3 was chlorinated by MgCl2 and formed DyCl3. XRD pattern of non-dissolved residue, which was left after the melts were washed with water to remove the soluble salt, showed that the new compounds (i.e., DyOCl, MgO, and Dy(OH)3) were produced. The concentration of Dy(III) reached a maximum when the concentration of Mg(II) ions exceeded 8?×?10?4 mol cm?3 in melts by inductive coupled plasma atomic emission spectrometer analyses of melts. Galvanostatic electrolysis was conducted to extract Dy element from LiCl–KCl–MgCl2–Dy2O3 melts by forming Mg–Li–Dy alloys. The components of Dy and Li in alloys were controlled within a small range by the concentration of MgCl2 in melts, current density, and additions of Dy2O3. XRD patterns of alloys indicated that Mg3Dy phase was formed. Scanning electron microscope images with energy-dispersive X-ray spectroscopy showed that Dy elements were mainly distributed in the grain boundary. Grain size was refined, due to a more content of Dy elements in alloys by optical microscopy images. 相似文献
4.
S. S. Belevskii Zh. I. Bobanova V. A. Buravets A. V. Gotelyak V. V. Danil’chuk S. A. Silkin A. I. Dikusar 《Russian Journal of Applied Chemistry》2016,89(9):1427-1433
Conditions were determined in which an active anodic dissolution of tungsten is observed in a borongluconate electrolyte used to obtain Co–W coatings (pH ~6.5) and the nature of critical currents of transition to the passivation was found, which makes it possible to use the tungsten anode as a soluble electrode. The anodic dissolution of tungsten occurs under these conditions with a current efficiency of 90–100%, which, in contrast to the case of a graphite anode, does not lead to an additional oxidation of the electrolyte components and polymerization in solution; in combination with the decrease in the concentration of tungstate ions, this reduces the electrolyte performance. It was shown that the use of a soluble tungsten anode in obtaining nanocrystalline cobalt–tungsten coating can improve the electrolyte performance due to the rise in the current efficiency of electrodeposition and to the increase in the microhardness of the coatings in comparison with the case of an insoluble graphite anode. 相似文献
5.
The cathodic reduction of YBa2Cu3O7 in aqueous electrolytes at ambient temperature turns out to be strongly dependent upon current density with respect to the
reaction mechanism. At low current density, topotactic electron/proton transfer is the dominant process, while at higher current
densities, two competing reactions appear, i.e. the topotactic conversion and an irreversible reaction leading to products
amorphous in terms of X-ray diffraction.
Received: 21 April 1999 / Accepted: 7 June 1999 相似文献
6.
The process of deposition of the Re–Ni alloy, its current efficiency, and the alloy composition are studied as a function of the current density and the solution temperature. The hydrogen content in the deposits, their surface morphology, internal structure, and properties as the cathodic material for HER are examined. It is assumed that besides the high rhenium content, the high catalytic activity of nickel–rhenium alloys is associated with the high degree of their structural disordering. 相似文献
7.
Kinetics of the Sn-Sb alloy electrodeposition from sulfate electrolytes containing organic additives (syntanol DS-10, Formalin,
1,4-butynediol) is studied by the faradaic impedance method. Bright Sn-Sb alloy coatings are plated in this electrolyte at
ic = 0.5-5 A/dm2. With increasing ic, the Sb content in the alloy decreases from 14 to 6.6 wt % 相似文献
8.
A. V. Karakurkchi M. V. Ved’ N. D. Sakhnenko I. Yu. Yermolenko 《Russian Journal of Applied Chemistry》2015,88(11):1860-1869
Specific features of the electrodeposition of iron–molybdenum–tungsten coatings from citrate electrolytes based on iron(III) sulfate in the dc mode and with a unipolar pulsed current were studied. It was shown that varying the relative concentrations of salts of alloy-forming metals and the solution pH makes it possible to obtain lustrous compact coatings with low porosity and various contents of high-melting components. The effect of temperature on the coating composition and current efficiency was examined. The current density ranges providing high electrolysis efficiency were found and it was demonstrated that using a pulsed current favors formation of more compositionally homogeneous surface layers at a smaller amount of adsorbed nonmetallic impurities in the coatings. The iron–molybdenum–tungsten coatings are X-ray-amorphous and have better physicomechanical properties and corrosion resistance as compared with the base, which makes it possible to recommend these coatings for application in techniques for surface reinforcement and restoration of worn-out articles. 相似文献
9.
N. Tsyntsaru 《Russian Journal of Electrochemistry》2016,52(11):1041-1047
Applying electrochemically deposited coatings is a convenient way to improve surface properties of a substrate metal. Today materials for applications are frequently selected according to their functional properties. Nowadays theoretical and practical studies of the co-deposition of tungsten with iron group metals are conducted worldwide, and interest for these studies increases. Tungsten alloys of iron group metals have a high melting point and are often considered high-performance alloys, and the attractiveness in those has been driven by their outstanding properties and multiple possible applications. That research is encouraged by the pronounced mechanical, tribological, and magnetic properties as well as the corrosion resistance of tungsten alloys. The magnetic properties of electrodeposited Co–W alloys are of interest in recording media and remotely-actuated micro-/nano-electromechanical systems. The given research presents an overview of versatile possibilities of Co–W alloys as multiscale materials obtained by electrodeposition from citrate solutions at pH 5–8 and temperatures 20–60°C. The paper discusses electrodeposited tungsten alloys as suitable candidates to meet many technological demands at macro-, micro- and nano-scale as coating films, microbumps and nanowires. 相似文献
10.
R. F. Shekhanov S. N. Gridchin A. V. Balmasov 《Russian Journal of Electrochemistry》2018,54(4):355-362
The electrodeposition of zinc–nickel alloys (5–16 at % Ni) from the ammonium oxalate electrolytes is studied. It is shown that the ratio between the alloy components has an effect on the corrosion resistance of the coatings, their structure, chemical and phase composition, and microhardness. 相似文献
11.
《Physics and Chemistry of Liquids》2012,50(4):333-342
A theoretical formalism that links thermodynamic properties to transport properties has been used to study the viscosity of Sn–Zn and In–Zn liquid alloys at various temperatures. The formalism was successful at describing the thermodynamic properties of these alloys and showed a better estimation of the viscosity of the Sn–Zn alloy than that of the In–Zn alloy. 相似文献
12.
Edigaryan A. A. Lubnin E. N. Polukarov Yu. M. 《Russian Journal of Electrochemistry》2001,37(7):710-714
As shown by scanning Auger electron microscopy and Auger electron spectroscopy, multilayered Ni–Cr thin films can be deposited under the action of periodic currents from sulfate–oxalate solutions containing nickel and chromium ions. The chromium-rich layers have an amorphous structure. In the nickel/chromium interphase region, the carbon content is elevated. Nickel layers contain admixtures of a hydroxide nature. 相似文献
13.
Tetsuya Tsuda Susumu Kuwabata Gery R. Stafford Charles L. Hussey 《Journal of Solid State Electrochemistry》2013,17(2):409-417
The electrochemistry of Hf(IV) and the electrodeposition of Al–Hf alloys were examined in the Lewis acidic 66.7–33.3 mol% aluminum chloride-1-ethyl-3-methylimidazolium chloride molten salt containing HfCl4. When cyclic staircase voltammetry was carried out at a platinum disk electrode in this melt, the deposition and stripping waves for Al shifted to negative and positive potentials, respectively, suggesting that aluminum stripping is more difficult due to the formation of Al–Hf alloys. Al–Hf alloy electrodeposits containing ~13 at.% Hf were obtained on Cu rotating wire and cylinder electrodes. The Hf content in the Al–Hf alloy deposits depended on the HfCl4 concentration in the melt, the electrodeposition temperature, and the applied current density. The deposits were composed of dense crystals and were completely chloride-free. The chloride-induced pitting corrosion potential of the resulting Al–Hf alloys was approximately +0.30 V against pure aluminum when the Hf content was above 10 at.%. 相似文献
14.
Four contemporary examples, all published in recent years, of studies of molecular electronics at electrode–electrolyte interfaces are reviewed in this opinion article. The first illustrative example involves the switching of the redox active molecular wire between redox states, with concomitant changes in molecular conductance. This example illustrates how molecular electronics at electrode–electrolyte interfaces can be used to analyse mechanisms of electron transfer, to distinguish electrolyte effects and to provide details not readily available from ensemble measurements. The second example shows that the fluctuations of molecular conductance of a redox active molecular wire can be followed as a function of electrode potential. This shows how the stochastic kinetics of individual reaction events at electrode–electrolyte interfaces can be followed. The third example demonstrates how electrochemistry can be used to control quantum interference in single molecular wires. The fourth example shows a single-molecule electrochemical transistor concept for well-defined metal cluster containing molecular wires. 相似文献
15.
Electrochemically deposited Zn–Co alloys under various deposition conditions were investigated using anodic linear sweep voltammetry
for phase structure determination, scanning electron microscopy for surface morphology analysis, atomic absorption spectroscopy
for determination of chemical composition, and polarization measurements and open circuit potential measurements for determination
of corrosion properties. The influence of deposition current density, temperature, and composition of deposition solution
on the phase structure and corrosion properties of Zn–Co alloys was studied. It was shown that the ratio of cobalt to zinc
ions in the plating bath strongly affects the chemical content and phase structure, as well as corrosion stability, of Zn–Co
alloys. Zn–Co alloys deposited from plating baths with the lowest and the highest ratios of cobalt and zinc ions exhibited
the lowest corrosion rate. 相似文献
16.
Ljubiša Balanović Dragana Živković Dragan Manasijević Duško Minić Vladan Ćosović Nadežda Talijan 《Journal of Thermal Analysis and Calorimetry》2014,118(2):1287-1292
The results of calorimetric study of binary Al–Zn system done according to the Oelsen thermodynamic method are presented in this paper. Main thermodynamic properties, including activities, activity coefficients, partial/integral molar Gibbs excess, and mixing energies were determined at 1,000 K. Positive deviation from Raoult law was noticed, with minimal values of ΔG M about ?3 kJ mol?1 and maximal values of ΔG E about +2 kJ mol?1. The energetics of mixing in liquid Al–Zn alloys has been analyzed through the study of concentration fluctuation in the long-wavelength limit, and weak affinity between Al and Zn atoms in the system was observed. Differential thermal analysis and light optic microscopy were applied in the frame of characterization of investigated binary alloys and phase diagram examination, and the results obtained were in accordance with available literature data. 相似文献
17.
Zheng Jianing Yin Taiqi Wang Pu Yan Yongde Smolenski Valeri Novoselova Alena Zhang Milin Ma Fuqiu Xue Yun 《Journal of Solid State Electrochemistry》2022,26(4):1067-1074
Journal of Solid State Electrochemistry - The electrochemical behavior of Yb(III) was studied at a W electrode in LiCl–KCl–ZnCl2 molten salt system. Cyclic voltammetry, square wave... 相似文献
18.
Yuriy Plevachuk Vasyl Sklyarchuk Ihor Shtablavyi Stepan Mudry Jürgen Brillo Hidekazu Kobatake 《Physics and Chemistry of Liquids》2016,54(4):440-453
The Co–Sn system is an important subsystem for Sn-based anode materials of lithium-ion batteries. Experimental results on the physical–chemical properties of this system in the liquid state, however, are rather sparse. In this work, the atomic structure and structure-sensitive thermophysical properties (viscosity, electrical resistivity, and thermoelectric power) of liquid Co–Sn alloys were investigated in a wide temperature range with special attention to the melting-solidification region. The obtained experimental results were combined with differential thermal analysis (DTA) data in order to verify the liquidus curve in the Sn-rich part of the Co–Sn phase diagram. 相似文献
19.
Conductivities of concentrated solutions of lithium chloride in glycerol were measured for concentrations ranging from 0.005 to 1.5 mol.dm?3. The conductivity dependencies were analysed successively using the Debye–Huckel–Onsager limiting law (DHO) at very low concentrations, the Fuoss equation of 1978 up to 0.1 mol.dm?3, the Casteel–Amis empirical equation and the quasi-lattice model (QLM) at moderate and higher concentrations. The molar conductivities at infinite dilution, obtained using DHO and QLM were quite different from each other, because the salt forms contact pairs which were underestimated in the Λ = f(C1/3) in QLM, as it may well be proved by Raman spectroscopy. Besides, the value of Madelung constant suggests that LiCl crystallises face centred cubic (FCC) at higher concentrations. On the basis of Raman spectroscopy analysis of previous lithium salts, we assume that the dissociation coefficient varies slightly with concentration and fraction of paired ion constant, the QLM equation is applied successfully in the concentration range used in this study. The temperature dependency of conductivity was also described using the Vogel–Tamman–Fulcher (VTF) empirical equation where the Arrhenius type was found. The results also suggest that as NaCl, LiCl can be considered as a structure maker electrolyte. 相似文献
20.
A. V. Gotelyak S. A. Silkin E. A. Yakhova A. I. Dikusar 《Russian Journal of Applied Chemistry》2017,90(4):541-546
The optimal pH value of the concentrated boron–gluconate bath for electroplating Co–W coatings is established to be 6.5 (the concentrations of the alloying components are raised by a factor of 5 compared with the commonly used electrolyte). The microhardness of binary Co–W alloys obtained from this bath reaches 1000 kg mm–2, and electrodeposition proceeds with high current efficiency ( 93–95%). We demonstrate the critical role the volume current density plays in determining the microhardness of the binary coatings electrodeposited from this bath under galvanostatic conditions. We attribute this peculiarity of the investigated system to microhardness size effect, which is associated with structural modifications in the plated coatings that can be induced by changing the volume current density. Using the concentrated bath improves efficiency of electrodeposition. 相似文献