Copper Selenocyanate Formation on the Copper Anode.

1997 ◽  
Vol 50 (4) ◽  
pp. 321 ◽  
Author(s):  
Paul A. Kilmartin ◽  
Graham A. Wright

The formation of CuSeCN on a copper anode was studied in 0·1 and 0·5 mol dm-3 KSeCN solutions. A thin film of polycrystalline CuSeCN was produced with a midpoint potential between the anodic and cathodic peaks for 0·1 mol dm-3 KSeCN at - 0·253 V, close to the open-circuit potential of - 0·249 V. A precursory anodic peak or shoulder was seen at about - 0·210 V, and was ascribed to the formation of a primary (barrier) film. The anodic peak currents for the primary film were linearly dependent upon the sweep rate. Potential steps into the primary film region produced current transients, with the current decaying in proportion to the reciprocal of time. The anodic peak current and potential for the secondary polycrystalline film were proportional to the square root of the sweep rate, an effect which is consistent with a model for porous film growth controlled by the resistance across the underlying barrier film. A weak Raman band due to Se-bonded CuSeCN at 2164 cm-1 was also observed in situ.

Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.


Author(s):  
Michael T. Marshall ◽  
Xianghong Tong ◽  
J. Murray Gibson

We have modified a JEOL 2000EX Transmission Electron Microscope (TEM) to allow in-situ ultra-high vacuum (UHV) surface science experiments as well as transmission electron diffraction and imaging. Our goal is to support research in the areas of in-situ film growth, oxidation, and etching on semiconducter surfaces and, hence, gain fundamental insight of the structural components involved with these processes. The large volume chamber needed for such experiments limits the resolution to about 30 Å, primarily due to electron optics. Figure 1 shows the standard JEOL 2000EX TEM. The UHV chamber in figure 2 replaces the specimen area of the TEM, as shown in figure 3. The chamber is outfitted with Low Energy Electron Diffraction (LEED), Auger Electron Spectroscopy (AES), Residual Gas Analyzer (RGA), gas dosing, and evaporation sources. Reflection Electron Microscopy (REM) is also possible. This instrument is referred to as SHEBA (Surface High-energy Electron Beam Apparatus).The UHV chamber measures 800 mm in diameter and 400 mm in height. JEOL provided adapter flanges for the column.


2021 ◽  
Vol 882 ◽  
pp. 96-103
Author(s):  
A.D. Vishwanatha ◽  
D.M. Shivanna ◽  
Bijayani Panda

In-situ AlxNiy reinforced aluminium matrix composites (AMCs) were produced by stir-casting route by adding 5, 10 and 15 weight percentage (wt.%) of Ni to AA6061 aluminum alloy. The density, porosity, microstructure, hardness and corrosion behaviour of the as-cast AMCs was studied and compared with that of the as-cast AA6061 alloy. The porosity in all the castings was found to be less than 0.1%. Further, the porosity was found to decrease with increase in Ni addition. Optical microscopy studies showed that in-situ formed AlxNiy was distributed along the dendritic arms. The distribution became non-homogeneous and coarse with increase in AlxNiy content. The coarse distribution of AlxNiy in the AA6061 matrix also resulted in the decrease in hardness of the composite, after an initial increase in hardness till 10 wt.% Ni addition. The open circuit potential (OCP) and corrosion potential (Ecorr) of the AMCs with 5, 10 and 15 wt. of % Ni addition was noble than that of the AA6061 alloy. This was understood to be due to the presence of AlxNiy intermetallic which is known to have a noble corrosion potential than the aluminium alloy. However, the corrosion current (icorr) increased while the polarization resistance (Rp) decreased with increase in Ni addition in the AMC. This indicates that the coarse non-homogeneous distribution of in-situ AlxNiy had a detrimental effect on the corrosion performance of the AMCs.


2002 ◽  
Vol 715 ◽  
Author(s):  
W.M.M. Kessels ◽  
P.J. van den Oever ◽  
J.P.M. Hoefnagels ◽  
J. Hong ◽  
I.J. Houston ◽  
...  

AbstractPlasma and in situ film studies have been applied to the expanding thermal plasma to obtain basic insight into the deposition of a-Si:H and μc-Si:H at high rates (> 10 Å/s). A study of the density of plasma radicals (Si, SiH, SiH3) and of the radicals' surface reactivity has revealed that SiH3 is the most important radical for the growth of both materials. In situ attenuated total reflection infrared spectroscopy and spectroscopic ellipsometry have revealed a thick interface layer and consequently long incubation time for the materials deposited at a high deposition rate.


1964 ◽  
Vol 19 (7-8) ◽  
pp. 835-843 ◽  
Author(s):  
H. Poppa

Early stages of oriented overgrowth of Ag, Au, and Pd on thin, single-crystal substrates of mica, molybdenite, Au and Pd were studied by high-resolution electron microscopy and diffraction. Cleaning of substrate surfaces and deposition of evaporated materials were conducted inside an electron microscope. High-magnification, continuous observation during growth permitted investigation of the kinetics of growth. A number of probably elementary epitaxial processes were studied in detail. Nucleation and growth behavior was examined for different supersaturations and free surface energies of substrate and overgrowth materials. The influence of alloying on growth and the spacing of parallel moiré structures was investigated.


1999 ◽  
Vol 433-435 ◽  
pp. 770-774 ◽  
Author(s):  
I.D Baikie ◽  
U Petermann ◽  
B Lägel

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