Photoemission Study of Low-Fluence, Non-Thermal Laser Damage of UHV-Cleaved Gallium Arsenide (110)

1990 ◽  
Vol 201 ◽  
Author(s):  
S. S. Goldenberg ◽  
J. P. Long ◽  
M. N. Kabler
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gallium Arsenide ◽  
Temperature Rise ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Laser Damage ◽  
Laser Fluences ◽  
Photoemission Study ◽  
Scanning Electron

AbstractThe pulsed-laser induced photochemical production of metallic Ga islands on the surface of GaAs cleaved, irradiated, and studied in ultrahigh vacuum (UHV) is documented through photoelectron spectroscopy and subsequent scanning electron microscopy. Ga islands are detected for laser fluences as low as 1 mJ/cm2, far below those previously reported for modification of GaAs, and for which the temperature rise is negligible.

scholarly journals Investigation of Spin Coating Cerium-Doped Hydroxyapatite Thin Films with Antifungal Properties

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 464
Author(s):  
Simona Liliana Iconaru ◽  
Mihai Valentin Predoi ◽  
Patrick Chapon ◽  
Sofia Gaiaschi ◽  
Krzysztof Rokosz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Spin Coating ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
X Ray ◽  
Antifungal Properties ◽  
Scanning Electron

In this study, the cerium-doped hydroxyapatite (Ca10−xCex(PO4)6(OH)2 with xCe = 0.1, 10Ce-HAp) coatings obtained by the spin coating method were presented for the first time. The stability of the 10Ce-HAp suspension particles used in the preparation of coatings was evaluated by ultrasonic studies, transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The surface morphology of the 10Ce-HAp coating was studied by SEM and atomic force microscopy (AFM) techniques. The obtained 10Ce-HAp coatings were uniform and without cracks or unevenness. Glow discharge optical emission spectroscopy (GDOES) and X-ray photoelectron spectroscopy (XPS) were used for the investigation of fine chemical depth profiling. The antifungal properties of the HAp and 10Ce-HAp suspensions and coatings were assessed using Candida albicans ATCC 10231 (C. albicans) fungal strain. The quantitative antifungal assays demonstrated that both 10Ce-HAp suspensions and coatings exhibited strong antifungal properties and that they successfully inhibited the development and adherence of C. albicans fungal cells for all the tested time intervals. The scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) visualization of the C. albicans fungal cells adherence to the 10Ce-HAp surface also demonstrated their strong inhibitory effects. In addition, the qualitative assays also suggested that the 10Ce-HAp coatings successfully stopped the biofilm formation.

scholarly journals Antibacterial activity of zinc oxide nanoparticles obtained by pulsed laser ablation in water and air

2018 ◽  
Vol 243 ◽  
pp. 00017 ◽  
Author(s):  
Daria Goncharova ◽  
Ekaterina Gavrilenko ◽  
Anna Nemoykina ◽  
Valery Svetlichnyi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antibacterial Activity ◽  
Laser Ablation ◽  
Zno Nanoparticles ◽  
Antibacterial Properties ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Composition And Structure ◽  
Scanning Electron

The paper studies physicochemical and antibacterial properties of ZnO nanoparticles obtained by pulsed laser ablation in water and air. Their composition and structure were studied by X-ray diffraction, transmission and scanning electron microscopy. Antibacterial activity of the nanoparticles was examined by its affection on Gram-positive Staphylococcus aureus (S.aureus). The dependence of nanoparticles’ physical and chemical antibacterial properties on the conditions of the ablation was shown. The model materials for the antibacterial bandage were made of cotton, filter paper and biodegradable polymer scaffolds (poly-l-lactide acid), and then they were coated with the obtained ZnO nanoparticles. The model bandage materials were examined by the scanning electron microscopy method and their antibacterial activity (ISO 20743:2013) was determined. High activity of all the samples against S.aureus was proved.

scholarly journals Improvement of the Space Charge Suppression and Hydrophobicity Property of Cellulose Insulation Pressboard by Surface Sputtering a ZnO/PTFE Functional Film

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1610 ◽  
Author(s):  
Li ◽  
Hao ◽  
Zhang ◽  
Hou ◽  
Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Space Charge ◽  
Photoelectron Spectroscopy ◽  
Power Transformers ◽  
Nano Structure ◽  
X Ray ◽  
Ptfe Composite ◽  
Cellulose Insulation ◽  
Scanning Electron

Oil-impregnated cellulose insulation polymer (oil-paper/pressboard insulation) has been widely used in power transformers. Establishing effective ways of improving the physical and chemical properties of the cellulose insulation polymer is currently a popular research topic. In order to improve the charge injection inhibition and hydrophobic properties of the cellulose insulation polymer used in power transformers, nano-structure zinc oxide (ZnO) and polytetrafluoroethylene (PTFE) films were fabricated on a cellulose insulation pressboard surface via reactive radio frequency (RF) magnetron sputtering. Before the fabrication of their composite film, Accelrys Materials Studio (MS) software was applied to simulate the interaction between the nanoparticles and cellulose molecules to determine the depositing sequence. Simulation results show that the ZnO nanoparticle has a better adhesion strength with cellulose molecules than the PTFE nanoparticle, so ZnO film should be sputtered at first to fabricate the ZnO/PTFE composite film for better film quality. The sputtered, thin films were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The space charge injection behavior and the hydrophobicity performance of the untreated pressboard; and the cellulose insulation pressboard with sputtered nano-structure ZnO, PTFE, and the ZnO/PTFE functional films were compared with each other. X-ray photoelectron spectroscopy results showed that ZnO, PTFE, and ZnO/PTFE functional films were all successfully fabricated on the cellulose insulation pressboard surface. Scanning electron microscopy and XRD results present the nano-structure of the sputtered ZnO, PTFE, and ZnO/PTFE functional films and their amorphous states, respectively. The ZnO/PTFE composite functional film shows an apparent space charge suppression effect and hydrophobicity. The amount of the accumulated space charge in the pressboard sputtered ZnO/PTFE composite functional film decreased by about 40% compared with that in untreated cellulose insulation pressboard, and the water contact angle (WCA) increased from 0° to 116°.

Characterization of Multiple Functional Solid Line of Graphite Ink Surface Printed by Micro-Flexographic

2015 ◽  
Vol 752-753 ◽  
pp. 1379-1383
Author(s):  
M.I. Maksud ◽  
Mohd Sallehuddin Yusof ◽  
Zaidi Embong
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Printing Plate ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Flexographic Printing ◽  
Scanning Electron

The purpose of this paper is to study a ink surface morphology, quantify the chemical composition involved in processing of graphite ink printed by flexographic printing. The methodology is to use surface sensitive technique, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) and Field Emission Scanning Electron Microscopy (FESEM). As a finding we successfully achieved 25 micron lines array using PDMS printing plate. The Originality and value of this work is surface sensitive techniques like XPS, AFM and FESEM were exclusively used in order to characterize graphite inks printed by flexographic method, using PDMS printing plate.

IDENTIFY OF THE MICRO-DEFECTS IN SEMI-INSULATING GaAs

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4484-4486
Author(s):  
YUESHENG XU ◽  
CHUNLING ZHANG ◽  
LEI TANG ◽  
CAICHI LIU ◽  
JINGCHEN HAO
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gallium Arsenide ◽  
Strong Interaction ◽  
Chemical Etching ◽  
Experimental Results ◽  
Transmission Electron ◽  
Koh Etching ◽  
Scanning Electron

The micro-defects in semi-insulating gallium arsenide (SI-GaAs) were investigated by means of chemical etching (ultrasonic aided Abtahams-Buiocchi etching, melting KOH etching), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The experimental results showed that the micro-defects in SI-GaAs are micro-precipitates of As with the size of microns. Micro-defects and dislocations have strong interaction, dislocations absorb the micro-defects and micro-defects decorate on the dislocations.

scholarly journals Preparation of Cerium Dioxide Layers on Titanium by Electrodeposition with Organic Solution

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Vaijayanti Namdeo Nande ◽  
Diana Kostyukova ◽  
Jeonghee Choi ◽  
Yong Hee Chung
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Cerium Dioxide ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Organic Solution ◽  
X Ray ◽  
Titanium Foils ◽  
Scanning Electron

Layers of cerium dioxide nanoparticles were prepared on titanium by electrodeposition with organic solution. Three concentrations of cerium ions were used at 31.6 V. The organic solution was isobutanol and titanium foils were used as anodes and cathodes. Currents were monitored during the electrodeposition. Deposition times ranged from 0.5 to 8 h. Deposited Deposited layers were calcined at 700 K for 30 min. The morphology and composition of the deposited layers were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). As-prepared and calcined deposition layers were assayed to be cerium dioxide. The average crystallite size increased from 4 to 7 nm through calcination at 700 K. Sizes of calcined cerium oxide agglomerates were ranging from 73 to 146 nm for 30 min deposition and 209 to 262 nm for 8 h deposition. The electrodeposition efficiencies of 0.5 h deposition at three concentrations were measured to be highest.

Synthesis of Nanophase Noble Metal Systems Utilizing Porous Silicon

1996 ◽  
Vol 457 ◽  
Author(s):  
I. Coulthard ◽  
T. K. Sham
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Porous Silicon ◽  
Noble Metal ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Visible Range ◽  
X Ray ◽  
Metallic Salt ◽  
Scanning Electron

ABSTRACTApart from its well known ability to luminesce very intensely at room temperature in the visible range, porous silicon is also an effective reducing agent. We report the formation of several noble metal (Pd, Ag, Au, Pt) nanostructures by reductive dispersion of metal ions from aqueous solutions onto the surface of porous silicon. The nanophase systems produced by reductive deposition vary with the element deposited and the metallic salt utilized in the process. The resulting nanophase systems were studied using a variety of techniques including: scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and spectroscopie methods using synchrotron radiation.

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