Scanning Electron Microscopy of Single-Crystal NiO Energetics

Author(s):  
L. E. Murr ◽  
C.J. Miglionico

The fusion of NiO powder in an oxygen-rich oxy-hydrogen flame at ∼2000°C at atmospheric pressure has been observed to produce, in addition to single-crystal Ni growth, a residual (001) vicinal NiO growth which exhibits an intergrowth and regrowth of isolated particles characterized as equilibrium (regular-faced) polyhedra, and a prominent “negative crystal” phenomena in the vicinal faces of the oxide. Observations of the NiO crystal growth and particle morphologies were made in a JE0L-JSM-50A scanning electron microscope operated at 25 kV in the secondary electron emission mode. The samples were uncoated.Figure 1(a) shows typically the NiO growth phenomena observed, while Fig. 1(b) illustrates the vicinal-surface growth features schematically. The major structural features can be characterized as terraces, ledges, and kinks, with "negative" growth features related to systematic terrace-atom desorption.

Author(s):  
V. Annamalai

Iron has been the major source of the precipitant metal in the copper cementation process. Aluminum, due to its abundant availability in the form of beverage cans, has been used successfully in the process in laboratory experiments1. In a recent study of the cementation of the Cu2+/pure A1 system2, it was found that the reaction rates followed a distinct two-step rate mechanism. This paper presents a physical explanation of the two-step rate mechanism on the basis of the structural characteristics of the copper deposits.A specially designed cementation cell along with aluminum (99.99% pure) rotating discs was used in this study2. Ultrasonic experiments were conducted using an 80 watt Bransonic 12 ultrasonic cleaner. Copper deposits were examined in a Hitachi Perkin-Elmer HHS-2R scanning electron microscope operated at 25 KV in the secondary electron emission mode.In most of the experiments, two distinct kinetic regions were observed, namely an initial slow rate followed by a final enhanced rate.


Author(s):  
V. Annamalai ◽  
L.E. Murr

Economical recovery of copper metal from leach liquors has been carried out by the simple process of cementing copper onto a suitable substrate metal, such as scrap-iron, since the 16th century. The process has, however, a major drawback of consuming more iron than stoichiometrically needed by the reaction.Therefore, many research groups started looking into the process more closely. Though it is accepted that the structural characteristics of the resultant copper deposit cause changes in reaction rates for various experimental conditions, not many systems have been systematically investigated. This paper examines the deposit structures and the kinetic data, and explains the correlations between them.A simple cementation cell along with rotating discs of pure iron (99.9%) were employed in this study to obtain the kinetic results The resultant copper deposits were studied in a Hitachi Perkin-Elmer HHS-2R scanning electron microscope operated at 25kV in the secondary electron emission mode.


Author(s):  
R. B. Neder ◽  
M. Burghammer ◽  
Th. Grasl ◽  
H. Schulz

AbstractWe developed a new micro manipulator for mounting individual sub-micrometer sized single crystals within a scanning electron microscope. The translations are realized via a commercially available piezomicroscope, adapted for high vacuum usage and realize nanometer resolution. With this novel instrument it is routinely possible to mount individual single crystals with sizes down to 0.1


Author(s):  
A. I. Tatarinov

With the help of the general and structurally-information schemes of remote control, an analysis was made in the course of which the requirements for protection against unauthorized access of the complex system were clarified and established. In the article structural features of the remote control system of mobile measuring points of rocket and space equipment are considered. These features are represented by the requirements for information protection, as well as the operating modes of this system. The list of these regimes was obtained as a result of studies of structural and functional schemes of a remote control system for mobile measuring points.


2011 ◽  
Vol 284-286 ◽  
pp. 1584-1587
Author(s):  
Zhen Xue Shi ◽  
Jia Rong Li ◽  
Shi Zhong Liu ◽  
Jin Qian Zhao

The specimens of low angle boundaries were machined from the second generation single crystal superalloy DD6 blades. The microstructures of low angle boundaries (LAB) were investigated from three scales of dendrite, γ′ phase and atom with optical microscopy (OM), scanning electron microscope (SEM), transition electron microscope (TEM) and high resolution transmission electrion microscopy (HREM). The results showed that on the dendrite scale LAB is interdendrite district formed by three dimensional curved face between the adjacent dendrites. On the γ′ phase scale LAB is composed by a thin layer γ phase and its bilateral imperfect cube γ′ phase. On the atom scale LAB is made up of dislocations within several atom thickness.


1988 ◽  
Vol 135 ◽  
Author(s):  
Michael M Thackeray

AbstractConsiderable efforts are in progress to develop rechargeable batteries as alternative systems to the nickel-cadmium battery. In this regard, several advances have been made in ambient-temperature lithium battery technology, and specifically in the engineering of rechargeable lithium/manganese dioxide cells. This paper reviews the current state of the art in rechargeable Li/MnO2battery technology; particular attention is paid to the structural features of various MnO2electrode materials which influence their electrochemical and cycling behaviour in lithium cells.


1993 ◽  
Vol 12 (2) ◽  
pp. 154-154
Author(s):  
Stephen Tatman

Abstract. The preparation of microfossil specimens for study with the scanning electron microscope involves the transfer of material from slides to stubs. Specimens must then be oriented and mounted securely. To do this accurately the slide and stub should both be viewed through a stereomicroscope. However due to differences in shape and height, both surfaces are not usually in the plane of focus at the same time. Many micropalaeontologists routinely use small boxes or sample tube lids to hold the stub and refocus before finally mounting the specimens. The risk of dropping specimens is reduced by using a single carrier, securely holding both the slide and stub. The design illustrated below (fig.1) was developed from a prototype constructed from cardboard and plastic. The metal unit can easily be made in a workshop at a very low cost or cardboard versions made in the laboratory.The stage is based on the principle that both slide and stub should be held securely, close together and in the same plane of focus. The slide holders should be secure but not too tight otherwise the stub may be jarred as slides are changed. The number of slides which can be held on one unit may be varied. The presence of two holders has proved useful, any more could make the unit cumbersome. If the microscope to be used does not have a wide stage then it may prove more practical to have only one holder.The stub holders allow the stub to be clamped to . . .


Author(s):  
Vladimir Yu. Sadovoy ◽  
Vladimir D. Blank ◽  
Sergey A. Terentiev ◽  
Dmitriy V. Teteruk ◽  
Sergey Yu. Troschiev

Dependence of secondary electron emission coefficient on the chosen crystallographic orientation for a synthetic single crystal diamond of type IIb, grown up by method of a temperature gradient, was investigated. The type IIb of single crystal diamond was chosen because of wide applicability in different areas of microelectronics and the semiconductor properties. Quantitative measurements of secondary electron emission coefficients with energy of primary beam about 7 keV and above for various crystallographic orientations was carried out: the highest coefficient of secondary electronic emission are recorded for the direction (100), cubic sector, and also in intergrowth area that is confirmed by a picture of distribution of the luminescence intensity for various sectors of a single crystal received by means of true secondary electrons detector of scanning electron microscope. The results for (100) area are outstanding: 8.18 at primary beam energy of 7 keV, 10.13 at 10 keV, 49.78 at 30 keV. The results for intergrowth area are similar: 10.10 at primary beam energy of 7 keV, 13.56 at 10 keV, 64.41 at 30 keV. The crystallographic directions (111) have shown secondary electron emission coefficient 4-6 times lower in comparison with (100) and intergrowth area: 2.54 on the average at primary beam energy of 7 keV, 2.75 at 10 keV, 10.03 at 30 keV. The non-standard behavior of secondary electron emission coefficient at the high energy primary beam for all orientations of single crystal diamond is shown: increase in secondary electron emission coefficient with increase in energy of primary beam. At the moment the reason of such behavior is not clear up to the end and since this fact causes a great interest of researchers, considerably expands applicability of the existing devices and detectors due to replacement of a functional element on diamond one, and also opens big opportunities for formation of new field of microelectronics, this facts demand further in-depth study by means of various methods of the structural and surface analysis.


2021 ◽  
Vol 2103 (1) ◽  
pp. 012124
Author(s):  
A Y Shmykov ◽  
S V Mjakin ◽  
N A Bubis ◽  
L M Kuztetzov ◽  
N A Esikova ◽  
...  

Abstract Oligomeric diisocyanate based coatings with different contents of barium titanate (BaTiO3) submicron sized particles as a ferroelectric filler are synthesized on poly(dimethylsiloxane) (PDMS) supports. The study of thus obtained coatings using confocal scanning electron microscopy allowed the characterization of their morphology and features of BaTiO3 particles distribution in the polymer binder, including the determination of threshold filler contents corresponding to the formation of an infinite cluster, matrix-island and chain-like structures as well as the percolation. Dielectric permittivity and dielectric losses of the composites are measured and studied depending on BaTiO3 filler content and relating structural features.


2019 ◽  
Vol 2 (1) ◽  
pp. 9-13
Author(s):  
Ni Made Dwidiani ◽  
Putu Wijaya Sunu ◽  
Gusti Ngurah Nitya Santhiarsa

This work studies the use of red chilli tree (capsicum anuumm L) waste as material of activated carbon and examines the morphological structure and elemental composition of the activated chili trees. The morphological structure was measured at TekMIRA (Pusat Penelitian dan Pengembangan Teknologi Mineral dan Batubara, Bandung) by using the scanning electron microscope (SEM), and the composition of the elements of carbon, hydrogen, nitrogen and ash is determined by the ultimate testing analysis with the ASTM D5373 standard. In the testing procedure, activated carbon is made from red chili tree waste by dehydration with a temperature of 2000 C for 1 hour and carbonized with a temperature of 3750 C for 1 hour. Then, the chemical activation (NaOH) is made in variation of concentration of 1%, 3%, and 5% with soaked time 24 hours, and dried at 2000 C for one hour. The carbonization at a concentration of 1% (NaOH) gave the best result on activated carbon from red chili trees.


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