The formation of copper aluminate by solid-state reaction

1991 ◽  
Vol 6 (9) ◽  
pp. 1958-1963 ◽  
Author(s):  
David W. Susnitzky ◽  
C. Barry Carter

Solid-state reactions between bulk samples of copper oxide and alumina have been studied using scanning electron microscopy and electron microprobe analysis. Both CuAl2O4 and CuAlO2 were found to form during reactions in air at 1100 °C between CuO powder and single-crystal alumina substrates. The relative position of the CuAl2O4 and CuAlO2 layers was observed to depend on the crystallographic orientation of the surface of the alumina substrate: CuAl2O4 formed in contact with (0001) alumina substrates while CuAlO2 formed when the alumina substrate surface was (110). Faceted Cu–aluminate/alumina phase boundaries were observed to develop when single-crystal alumina rods were reacted with CuO, although the interfaces invariably tended to be wavy.

Author(s):  
R. I. Johnsson-Hegyeli ◽  
A. F. Hegyeli ◽  
D. K. Landstrom ◽  
W. C. Lane

Last year we reported on the use of reflected light interference microscopy (RLIM) for the direct color photography of the surfaces of living normal and malignant cell cultures without the use of replicas, fixatives, or stains. The surface topography of living cells was found to follow underlying cellular structures such as nuceloli, nuclear membranes, and cytoplasmic organelles, making possible the study of their three-dimensional relationships in time. The technique makes possible the direct examination of cells grown on opaque as well as transparent surfaces. The successful in situ electron microprobe analysis of the elemental composition and distribution within single tissue culture cells was also reported.This paper deals with the parallel and combined use of scanning electron microscopy (SEM) and the two previous techniques in a study of living and fixed cancer cells. All three studies can be carried out consecutively on the same experimental specimens without disturbing the cells or their structural relationships to each other and the surface on which they are grown. KB carcinoma cells were grown on glass coverslips in closed Leighto tubes as previously described. The cultures were photographed alive by means of RLIM, then fixed with a fixative modified from Sabatini, et al (1963).


2020 ◽  
Vol 995 ◽  
pp. 89-93
Author(s):  
A.N. Jannah ◽  
S.A. Halim ◽  
H. Abdullah

In this study, pulsed laser deposition technique was used to deposit bismuth plumbum strontium calcium copper oxide {Bi (Pb)SrCaCu0} thin films on MgO single crystal substrate. Solid state procedure which is inexpensive technique used in the production process of the Bi (Pb)SrCaCu0 superconductor bulk sample. In this work, Handy YAG Lasers (model: HYL 101 E) has been used. It is a high power class 4 solid state (ND: YAG) Q-switched pulsed laser and 532 nm (visible green: second harmonic) has been used to ablate the films. The substrate used in this work was single crystal MgO with the (100) orientation. Scanning Electron Microscopy (SEM) was used to observe the microstructure of fracture surface and cross section of thin film materials. Variable Pressure Scanning Electron Microscope (LEO-VPSEM) was used to study the correlation between the microstructure features. SEM studies have shown that the surface morphology of the bulk sample comprises platelets of average size ≈10μm with uniform and homogenous microstructure. The typical morphology of the as deposited films showed a continuous phase, granular structure, which spherical particles up to 5μm in diameter. The most prominent types of particulates BPSCCO films on MgO substrate are droplets with smooth surface, bigger droplets with granular surface, spherically-shaped features confined by randomly oriented facets, submicron rod-like features, Cu-enriched needles, platelets, irregularly-shaped Cu-rich outgrowths, strongly Cu-enriched tabular outgrowths, big target fragments, island growth structure, cubic and rectangular cubic structures. SEM analysis also showed that the deposition time have a pronounced influence on the particle size. The target morphology, which develops under laser-irradiation, depends on the laser fluence and the technique, by which the laser beam is moved relatively to the target during ablation. Laser-irradiated surfaces normally become altered both physically and chemically and morphological changes take the form of periodic structures such as ripples and ridges.


2010 ◽  
Vol 74 (6) ◽  
pp. 969-978 ◽  
Author(s):  
I. E. Grey ◽  
W. G. Mumme ◽  
S. M. Neville ◽  
N. C. Wilson ◽  
W. D. Birch

AbstractSecondary phosphate assemblages from the Hagendorf Süd granitic pegmatite, containing the new Mn-Al phosphate mineral, nordgauite, have been characterized using scanning electron microscopy and electron microprobe analysis. Nordgauite nodules enclose crystals of the jahnsite—whiteite group of minerals, showing pronounced compositional zoning, spanning the full range of Fe/Al ratios between jahnsite and whiteite. The whiteite-rich members are F-bearing, whereas the jahnsite-rich members contain no F. Associated minerals include sphalerite, apatite, parascholzite, zwieselite-triplite solid solutions and a kingsmountite-related mineral. The average compositions of whiteite and jahnsite from different zoned regions correspond to jahnsite-(CaMnMn), whiteite-(CaMnMn) and the previously undescribed whiteite-(CaMnFe) end-members. Mo-Kα CCD intensity data were collected on a twinned crystal of the (CaMnMn)-dominant whiteite and refined in P2/a to wRobs = 0.064 for 1015 observed reflections.


1999 ◽  
Vol 586 ◽  
Author(s):  
C. Korte ◽  
J. K. Farrer ◽  
N. Ravishankar ◽  
J. R. Michael ◽  
H. Schmalzried ◽  
...  

ABSTRACTInterfaces play an important role in determining the effect of electric fields on the mechanism of the formation of spinel by solid-state reaction. The reaction occurs by the movement of phase boundaries but the rate of this movement can be affected by grain boundaries in the reactants or in the reaction product. Only by understanding these relationships will it be possible to engineer their behavior. As a particular example of such a study, Mgln2O4 can be formed by the reaction between single-crystal MgO substrate and a thin film of In2O3with or without an applied electric field. High-resolution backscattered electron (BSE) imaging and electron backscattered diffraction (EBSD) in a scanning electron microscope (SEM) has been used to obtain complementary chemical and crystallographic information.


2017 ◽  
Vol 265 ◽  
pp. 900-905
Author(s):  
O.V. Samoilova ◽  
G.G. Mikhailov ◽  
L.A. Makrovets

Using rare earth metals as deoxidizers is an efficient way of getting highly deoxidized copper melt required for certain bronzes production. Thermodynamic modeling of phase equilibria in the Cu–La–O system in the temperature range of 1100–1300 °С was performed to assess a possible depth of copper melt deoxidation with lanthanum, and also to determine the resulting oxide phases. During the experimental part of the work, Cu–La–O system metal samples were melted and then studied with the JEOL JSM 6460-LV scanning electron microscope equipped with the energy-dispersive spectrometer providing electron microprobe analysis to specify formed nonmetallic inclusion type.


2020 ◽  
Vol 49 (18) ◽  
pp. 5932-5938
Author(s):  
Yunwei Zhao ◽  
Pengfei Jiang ◽  
Wenliang Gao ◽  
Rihong Cong ◽  
Jing Ju ◽  
...  

A high level of Eu3+ (7 atom%) was doped successfully, suggesting the possible single crystal growth of bi-functional RE3+-doped δ-BiB3O6.


Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
Dimitrina Dimitrova ◽  
Vassilka Mladenova ◽  
Lutz Hecht

The colloform pyrite variety incorporates many trace elements that are released in the environment during rapid oxidation. Colloform pyrite from the Chiprovtsi silver–lead deposit in Bulgaria and its oxidation efflorescent products were studied using X-ray diffractometry, scanning electron microscopy, electron microprobe analysis, and laser ablation inductively coupled plasma mass spectrometry. Pyrite is enriched with (in ppm): Co (0.1–964), Ni (1.8–3858), Cu (2.9–3188), Zn (3.1–77), Ag (1.2–1771), As (8179–52,787), Se (2.7–21.7), Sb (48–17792), Hg (4–2854), Tl (1.7–2336), Pb (13–7072), and Au (0.07–2.77). Gypsum, anhydrite, szomolnokite, halotrichite, römerite, copiapite, aluminocopiapite, magnesiocopiapite, coquimbite, aluminocoquimbite, voltaite, and ammoniomagnesiovoltaite were identified in the efflorescent sulfate assemblage. Sulfate minerals contain not only inherited elements from pyrite (Cr, Fe, Co, Ni, Cu, Zn, Ag, In, As, Sb, Hg, Tl, and Pb), but also newly introduced elements (Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Mn, Ga, Rb, Sr, Y, Zr, Sn, Cs, Ba, REE, U, and Th). Voltaite group minerals, copiapite, magnesiocopiapite, and römerite incorporate most of the trace elements, especially the most hazardous As, Sb, Hg, and Tl. Colloform pyrite occurrence in the Chiprovtsi deposit is limited. Its association with marbles would further restrict the oxidation and release of hazardous elements into the environment.


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