scholarly journals Ultraviolet Irradiation on a Pyrite Surface Improves Triglycine Adsorption

Life ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 50 ◽  
Author(s):  
Santos Galvez-Martinez ◽  
Eva Mateo-Marti
Keyword(s):  
Functional Group ◽  
Chemical Species ◽  
Photoemission Spectroscopy ◽  
Molecular Adsorption ◽  
Surface Chemical ◽  
Pyrite Surface ◽  
Mineral Surface ◽  
Chemical Changes ◽  
X Ray ◽  
Highly Sensitive

We characterized the adsorption of triglycine molecules on a pyrite surface under several simulated environmental conditions by X-ray photoemission spectroscopy. The triglycine molecular adsorption on a pyrite surface under vacuum conditions (absence of oxygen) shows the presence of two different states for the amine functional group (NH2 and NH3+), therefore two chemical species (anionic and zwitterionic). On the other hand, molecular adsorption from a solution discriminates the NH2 as a unique molecular adsorption form, however, the amount adsorbed in this case is higher than under vacuum conditions. Furthermore, molecular adsorption on the mineral surface is even favored if the pyrite surface has been irradiated before the molecular adsorption occurs. Pyrite surface chemistry is highly sensitive to the chemical changes induced by UV irradiation, as XPS analysis shows the presence of Fe2O3 and Fe2SO4—like environments on the surface. Surface chemical changes induced by UV help to increase the probability of adsorption of molecular species and their subsequent concentration on the pyrite surface.

Nanofunctionalized Phosphor Particles for Advanced Display Applications

2001 ◽  
Author(s):  
Michael Ollinger ◽  
Valentin Craciun ◽  
Rajiv Singh
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Degradation Rate ◽  
Binding Energies ◽  
Xps Analysis ◽  
Surface Chemical ◽  
Chemical Changes ◽  
X Ray ◽  
Two Peaks

Abstract Cathodoluminescence (CL) degradation measurements showed that by applying a nano meter scale indium tin oxide (ITO) coating on micron sized ZnS:Ag particulates the degradation lifetime was dramatically improved. X-ray photoelectron spectroscopy (XPS) analysis showed that the Zn 2p3/2 and S 2p3/2 peaks of the degraded ZnS:Ag were shifted to higher binding energies, which correspond to oxidized elements, with respect to those found for as-received ZnS:Ag. The XPS analysis for the ITO coated ZnS:Ag showed a broadening of the Zn 2p3/2 and S 2p3/2 peaks, which were a convolution of two peaks. In this case, the Zn 2p3/2 and S 2p3/2 peaks corresponding to ZnS were still present together with a small shoulder corresponding to the oxidized elements. This difference in the XPS shows that the ITO coating reduced the degradation rate by slowing the surface chemical changes on the ZnS:Ag.

Scanning Auger Microscopy and X Ray Photoemission Spectroscopy Studies of Metallic Archaeomaterials

1996 ◽  
Vol 462 ◽  
Author(s):  
E. Paparazzo ◽  
L. Moretto
Keyword(s):  
Spatial Resolution ◽  
Chemical Species ◽  
Lateral Distribution ◽  
Photoemission Spectroscopy ◽  
X Ray ◽  
Lead Pipe ◽  
Iron Sample ◽  
Spectroscopy Studies ◽  
Auger Microscopy ◽  
Lead Oxidation

ABSTRACTWe report on the surface microchemistry of a Roman iron object and of a Roman lead pipe ‘fistula’. The original patina of the iron sample consists mainly of oxidic phases whose lateral distribution is imaged with a submicron spatial resolution. Metallic iron in the bare surface is covered with a Fe(lll)-Fe(ll) oxidic layer which is several times thicker than in a modern ferritic steel. We find that the presence of a flux minimizes lead oxidation in the joint of the fistula as well as in comparison, ‘modern’ lead soldered samples. In one of these comparison samples the lateral distribution of the chemical species present is imaged with a spatial resolution of about 1000 Å.

Pyrite surface environment drives molecular adsorption: cystine on pyrite(100) investigated by X-ray photoemission spectroscopy and low energy electron diffraction

2016 ◽  
Vol 18 (39) ◽  
pp. 27219-27225 ◽  
Author(s):  
M. Sanchez-Arenillas ◽  
E. Mateo-Marti
Keyword(s):  
Critical Parameter ◽  
Annealing Process ◽  
Low Energy ◽  
Photoemission Spectroscopy ◽  
Pyrite Surface ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Pre Treatment ◽  
Surface Environment

The annealing process for pre-treatment of pyrite surfaces is a critical parameter in promoting ordering on the surface and it has chemical implications on the cystine adsorbed molecules.

Chemical Species Identification in an SEM by Changes in Emitted X-Ray Energies

1974 ◽  
Vol 32 ◽  
pp. 570-571
Author(s):  
R. H. Duff
Keyword(s):  
Species Identification ◽  
Valence Electron ◽  
Chemical Species ◽  
X Rays ◽  
Chemical Bonds ◽  
Small Shift ◽  
X Ray ◽  
Electron Transitions ◽  
Peak Energy ◽  
Chemical Combination

A material irradiated with electrons emits x-rays having energies characteristic of the elements present. Chemical combination between elements results in a small shift of the peak energies of these characteristic x-rays because chemical bonds between different elements have different energies. The energy differences of the characteristic x-rays resulting from valence electron transitions can be used to identify the chemical species present and to obtain information about the chemical bond itself. Although these peak-energy shifts have been well known for a number of years, their use for chemical-species identification in small volumes of material was not realized until the development of the electron microprobe.

Estimation of the noise in TEM image recorded on “imaging plate”

1987 ◽  
Vol 45 ◽  
pp. 748-749
Author(s):  
T. Oikawa ◽  
N. Mori ◽  
T. Katoh ◽  
Y. Harada ◽  
J. Miyahara ◽  
...  
Keyword(s):  
Low Dose ◽  
Quantum Noise ◽  
Laser Light ◽  
Imaging Plate ◽  
Total System ◽  
Electron Dose ◽  
X Ray ◽  
Image Recording ◽  
Recording Material ◽  
Highly Sensitive

The “Imaging Plate”(IP) is a highly sensitive image recording plate for X-ray radiography. It has been ascertained that the IP has superior properties and high practicability as an image recording material in a TEM. The sensitivity, one of the properties, is about 3 orders higher than that of conventional photo film. The IP is expected to be applied to low dose techniques. In this paper, an estimation of the quantum noise on the TEM image which appears in case of low electron dose on the IP is reported.In this experiment, the JEM-2000FX TEM and an IP having the same size as photo film were used.Figure 1 shows the schematic diagram of the total system including the TEM used in this experiment. In the reader, He-Ne laser light is scanned across the IP, then blue light is emitted from the IP.

Synthesis and characterization of TiN / Ti / AISI 410 coatings

2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama
Keyword(s):  
Synthesis And Characterization ◽  
Photoemission Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Columnar Grains ◽  
Tin Thin Films ◽  
Steel Aisi ◽  
Interacting Surfaces ◽  
Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

Argon Plasma Induced Surface Modifications For Resistless Patterning Of Aluminium Films

1991 ◽  
Vol 223 ◽  
Author(s):  
Neeta Agrawal ◽  
R. D. Tarey ◽  
K. L. Chopra
Keyword(s):  
Etch Rate ◽  
Argon Plasma ◽  
Surface Modifications ◽  
Surface Chemical ◽  
Plasma Exposure ◽  
X Ray ◽  
Aluminium Fluoride ◽  
A New Technique ◽  
Plasma Exposure Time ◽  
Surface Chemical Modification

ABSTRACTArgon plasma exposure has been used to induce surface chemical modification of aluminium thin films, causing a drastic change in etch rate in standard HNO3/CH3COOH/H3PO4 etchant. The inhibition period was found to increase with power and Ar plasma exposure time. Auger electron and x-ray photoelectron spectroscopies have indicated formation of an aluminium fluoride (AlF3) surface layer due to fluorine contamination originating from the residue left in the plasma chamber during CF4 processing. The high etch selectivity between unexposed and argon plasma exposed regions has been exploited as a new technique for resistless patterning of aluminium.

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