scholarly journals Copper Oxides on a Cu Sheet Substrate Made by Laser Technique

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3794
Author(s):  
Małgorzata Musztyfaga-Staszuk ◽  
Damian Janicki ◽  
Katarzyna Gawlińska-Nęcek ◽  
Robert Socha ◽  
Grzegorz Putynkowski ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Copper Oxide ◽  
Diffraction Method ◽  
Band Gap Energy ◽  
Element Distribution ◽  
Copper Oxides ◽  
Laser Technique ◽  
Copper Oxidation ◽  
Oxide Layers ◽  
Distribution Maps

This paper presents results from the production of copper oxide layers on a Cu sheet substrate using diode and Yb:YAG disc lasers operating in the wavelength ranges of 808–940 nm and 1030 nm. The parameters of these layers were compared with the layer obtained in the thermal process of copper oxidation at 300 °C in an infrared (IR) furnace in a natural atmosphere. Investigations into the layers mentioned above, concerning their topography, chemical composition and roughness, were made using scanning electron microscopy (SEM) and atomic force microscopy (AFM). A hot-point probe was used to determine and check the type of conductivity of the copper oxide layers formed. The optical band gap energy was estimated by applying the Kubelka–Munk method based on spectrophotometric data. Cross-sections and the element distribution maps were made using transmission electron microscopy (TEM). The phase analysis was investigated by the X-ray diffraction method (XRD). In sum, controlled laser oxidations of copper sheets allow for the formation of a mixture of Cu2O and CuO phases. The diode laser allows the production of a layer of copper oxides with a phase composition comparable to the oxides produced by the thermal oxidation method, while the distribution of high phase uniformity in the cross-section of the layer enables the process using a Yb:YAG disc laser.

Surface reconstructions of (001) cleaved GdBa2Cu3O7-δ

1992 ◽  
Vol 50 (1) ◽  
pp. 106-107
Author(s):  
H.W. Zandbergen ◽  
M.R. McCartney
Keyword(s):  
Electron Microscopy ◽  
Copper Oxide ◽  
Grain Boundaries ◽  
Atomic Structure ◽  
Oxygen Deficiency ◽  
Surface Layers ◽  
Layer Sequence ◽  
Surface Reconstructions ◽  
Good Agreement

Very few electron microscopy papers have been published on the atomic structure of the copper oxide based superconductor surfaces. Zandbergen et al. have reported that the surface of YBa2Cu3O7-δ was such that the terminating layer sequence is bulk-Y-CuO2-BaO-CuO-BaO, whereas the interruption at the grain boundaries is bulk-Y-CuO2-BaO-CuO. Bursill et al. reported that HREM images of the termination at the surface are in good agreement with calculated images with the same layer sequence as observed by Zandbergen et al. but with some oxygen deficiency in the two surface layers. In both studies only one or a few surfaces were studied.

Investigation of Microbial Cellulose/Cotton/Silver Nanobiocomposite as a Modern Wound Dressing

2013 ◽  
Vol 829 ◽  
pp. 616-621 ◽  
Author(s):  
Ramin Khajavi ◽  
Amin Meftahi ◽  
Somayeh Alibakhshi ◽  
Leila Samih
Keyword(s):  
Electron Microscopy ◽  
Wound Dressing ◽  
Moisture Absorption ◽  
Diffraction Method ◽  
Test Method ◽  
Cellulose Synthesis ◽  
X Ray Diffraction ◽  
Microbial Cellulose ◽  
Antimicrobial Efficiency ◽  
Transmission Electron

In this study the nanobiocomposite of Microbial cellulose/Cotton/Silver is introduced as a modern wound dressing. Microbial cellulose was synthesized in situ on cotton gauze. The static medium culture (Hestrin & Scharm) and Acetobacter Xylinum used for microbial cellulose synthesis and 6 days formed layers used for experiments. Half of 6 days samples were reverse after 3 days in order to form double coated gauze. One or two coated sides specimens were deactivated purified and dipped in a 500ppm nanosilver concentration. Specimens were analyzed by X-ray diffraction method, Fourier transform infra-red spectroscopy, Scanning electron microscopy and transmission electron microscopy. Their water and moisture absorption determined and their antibacterial efficiency evaluated by AATCC 100 antibacterial test method. Results showed about 30% increase in water absorption with less than 8% moisture regain. Microscopic images showed a proper distribution of nanosilver without agglomerations at surface and inside nanobiocomposite which caused improved antimicrobial efficiency. The obtained results indicated that nanocomposite (double coated gauze) has high potential for applying as a modern wound dressing.

scholarly journals Cross-Sectional Information on Pore Structure and Element Distribution of Sediment Particles by SEM and EDS

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Minghong Chen ◽  
Huiming Zhao ◽  
Hongwei Fang ◽  
Yuefeng Zhang
Keyword(s):  
Pore Structure ◽  
Particle Surface ◽  
Element Distribution ◽  
Special Method ◽  
Cross Sectional ◽  
Distribution Maps ◽  
Observation Methods ◽  
Sediment Particles ◽  
Pore Microstructure ◽  
Physical And Chemical

The interaction between pollutants and sediment particles often occurs on the particle surface, so surface properties directly affect surface reaction. The physical and chemical processes occurring on sediment particle surfaces are microscopic processes and as such need to be studied from a microscopic perspective. In this study, field emission scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS) were adopted to observe and analyze the pore structure and element distribution of sediment particles. In particular, a special method of sample preparation was used to achieve the corresponding cross-sectional information of sediment particles. Clear images of a particle profile and pore microstructure were obtained by high-resolution SEM, while element distribution maps of sediment particles were obtained by EDS. The results provide an intuitive understanding of the internal microenvironment and external behavior of sediment particles, in addition to revealing a significant role of pore microstructure in the adsorption and desorption of pollutants. Thus, a combination of different experimental instruments and observation methods can provide real images and information on microscopic pore structure and element distribution of sediment particles. These results should help to improve our understanding of sediment dynamics and its environmental effects.

Recent X-ray diffraction studies of muscle

1968 ◽  
Vol 1 (2) ◽  
pp. 177-216 ◽  
Author(s):  
Jean Hanson
Keyword(s):  
Electron Microscopy ◽  
Diffraction Method ◽  
Artificial Muscle ◽  
Regular Structure ◽  
Normal Activity ◽  
Protein Crystal ◽  
Natural State ◽  
X Rays ◽  
X Ray Diffraction ◽  
Muscle Biology

An intact living muscle has such a regular structure that it diffracts light or X-rays, thereby providing patterns that contain uniquely valuable information. Interpretation of these patterns is not straightforward, but is helped by light microscopy and electron microscopy, which can often provide similar though less reliable information. At all levels of complexity, from that of the fibrils to that of the molecules, structure in a muscle is orderly. No other natural cell assembly is so suited to study by the diffraction method, and the results obtained in recent years are an outstanding example of how this method can elucidate a biological problem. In contrast to protein crystallography, where the system studied is artificial, muscle can be examined in its natural state, during normal activity. The levels of structure explored as yet in muscle are above that of the atoms in the molecules. Such structure is more commonly investigated by electron microscopy, and the application of the diffraction method to living muscle has provided a valuable check on the preparative artifacts that worry the microscopist. The great complexity of a muscle, as compared with a protein crystal, and the fact that the system is only semi-crystalline, giving a much less detailed diffraction pattern, make the problems of interpretation especially difficult. But a great deal of useful information is available about other properties of muscle and its constituents, and the flourishing state of muscle biology at present is a major factor contributing to the successful application of the diffraction method.

scholarly journals H<sub>2</sub>S dosimeter with controllable percolation threshold based on semi-conducting copper oxide thin films

2017 ◽  
Vol 6 (1) ◽  
pp. 163-170 ◽  
Author(s):  
Christoph Seitz ◽  
Giuliana Beck ◽  
Jörg Hennemann ◽  
Christian Kandzia ◽  
Karl P. Hering ◽  
...  
Keyword(s):  
Thin Films ◽  
Copper Oxide ◽  
Percolation Threshold ◽  
Structural Parameters ◽  
Electrical Conductance ◽  
Copper Oxides ◽  
Island Growth ◽  
Switching Behaviour ◽  
The Impact ◽  
H2s Detection

Abstract. Copper oxides, such as CuO and Cu2O, are promising materials for H2S detection because of the reversible reaction with H2S to copper sulfides (CuS, Cu2S). Along with the phase change, the electrical conductance increases by several orders of magnitude. On CuOx films the H2S reaction causes the formation of statistically distributed CuxS islands. Continuous exposition to H2S leads to island growth and eventually to the formation of an electrical highly conductive path traversing the entire system: the so-called percolation path. The associated CuOx ∕ CuxS conversion ratio is referred to as the percolation threshold. This pronounced threshold causes a gas concentration dependent switch-like behaviour of the film conductance. However, to utilize this effect for the preparation of CuO-based H2S sensors, a profound understanding of the operational and morphological parameters influencing the CuS path evolution is needed.Thus, this article is focused on basic features of H2S detection by copper oxide films and the influence of structural parameters on the percolation threshold and switching behaviour. In particular, two important factors, namely the stoichiometry of copper oxides (CuO, Cu2O and Cu4O3) and surface morphology, are investigated in detail. CuOx thin films were synthesized by a radio frequency magnetron sputtering process which allows modification of these parameters. It could be shown that, for instance, the impact on the switching behaviour is dominated by morphology rather than stoichiometry of copper oxide.

scholarly journals Electron Microscopy on Cu Element Distribution in Spheroidal Graphite Cast Iron

2020 ◽  
Vol 61 (9) ◽  
pp. 1853-1861
Author(s):  
Takeshi Nagase ◽  
Toru Maruyama ◽  
Kazunori Asano ◽  
Yoshio Igarashi
Keyword(s):  
Electron Microscopy ◽  
Cast Iron ◽  
Element Distribution ◽  
Spheroidal Graphite ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

Effect of Dibenzyl Disulfide Corrosion on Accelerated Thermal Aging Crosslinked Polyethylene Cable Materials with Copper Core and Insulation Layer

2020 ◽  
Vol 15 (11) ◽  
pp. 1406-1411
Author(s):  
Yi-Fan Cheng ◽  
Ling-Na Xu ◽  
Tian-En Chen ◽  
Guo-Zhen Jiang ◽  
Jia-Bin Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Thermal Aging ◽  
Fourier Transform Infrared ◽  
Element Distribution ◽  
Insulation Layer ◽  
Xlpe Cable ◽  
Scanning Electron ◽  
Accelerated Thermal Aging

Crosslinked polyethylene (XLPE) cable has been widely used and studied with its specific failure mechanism. Among them, although thermal aging of XLPE insulation materials has been widely studied, the effect of accelerated thermal aging on the sulfur corrosion of XLPE cable has not been studied much. For further understand the mechanism of sulfur corrosion, the accelerated thermal aging method was taken with 200 mg/kg DBDS based on the distinguish of temperature. The macro and micro analysis contrast test before and after corrosion were also taken to investigate the morphology difference, the element distribution, the influence of thermal aging and DBDS addition the corrosion of copper core, and the assessment of insulation layer was also carried out by Fourier transform infrared spectra and spectroscopy, scanning electron microscopy to distinguish the microstructure and composition. Under the accelerated thermal aging experiment with DBDS, both copper core and insulation layer of sample No. 1 exhibit the most serious corrosion and aging condition. On the surface of the copper core, the DBDS-Cu complexes decompose to produce Cu2S and the temperature has a direct effect on this reaction. The insulation layer of sample No. 1 showed the most severe aging situation, with characteristic peaks of carbonyl appearing at 1720 cm-1 in the Fourier transform infrared tests and more defects, holes and cracks found in spectroscopy, scanning electron microscopy images.

scholarly journals Characterization of Serpentines from Different Regions by Transmission Electron Microscopy, X-ray Diffraction, BET Specific Surface Area and Vibrational and Electronic Spectroscopy

Fibers ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 47 ◽  
Author(s):  
Miguel A. Rivero Crespo ◽  
Dolores Pereira Gómez ◽  
María V. Villa García ◽  
José M. Gallardo Amores ◽  
Vicente Sánchez Escribano
Keyword(s):  
Electron Microscopy ◽  
Relative Intensity ◽  
Electronic Spectroscopy ◽  
Visible Region ◽  
Band Gap Energy ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Oh Groups ◽  
X Ray ◽  
Xrd Patterns

Serpentinite powdered samples from four different regions were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), SBET and porosity measurements, UV-Vis and Infrared Spectroscopy of the skeletal region and surface OH groups. SEM micrographs of the samples showed a prismatic morphology when the lizardite was the predominant phase, while if antigorite phase prevailed, the particles had a globular morphology. The few fibrous-shaped particles, only observed by SEM and weakly detected by XRD on MO-9C and MO13 samples, were characteristic of the chrysotile phase. All diffraction XRD patterns showed characteristic peaks of antigorite and lizardite serpentine phases, with crystallite sizes in the range 310–250 Å and with different degrees and types of carbonation processes, one derived from the transformation of the serpentine, generating dolomite, and another by direct precipitation of calcite. The SBET reached values between 38–24 m2∙g−1 for the samples less crystalline, in agreement with the XRD patterns, while those with a higher degree of crystallinity gave values close to 8–9 m2∙g−1. In the UV region all electronic spectra were dominated by the absorption edge due to O2− → Si4+ charge transfer transition, with Si4+ in tetrahedral coordination, corresponding to a band gap energy of ca 4.7 eV. In the visible region, 800–350 nm, the spectra of all samples, except Donai, presented at least two weak and broad absorptions centred in the range 650–800 and 550–360 nm, associated with the presence of Fe3+ ions from the oxidation of structural Fe2+ ions in the serpentinites ((MgxFe2+1−x)3Si2O5(OH)4). The relative intensity of the IR bands corresponding to the stretching modes of the OH’s groups indicated the prevalence of one of the two phases, antigorite or lizardite, in the serpentinites. We proposed that the different relative intensity of these bands could be considered as diagnostic to differentiate the predominance of these phases in serpentinites.

Sign in / Sign up

Export Citation Format

Share Document