Observation of atomic-like transition in Sapphire crystal by deep UV photoluminescence spectroscopy

MRS Advances ◽  
2020 ◽  
Vol 5 (35-36) ◽  
pp. 1851-1857
Author(s):  
Nikesh Maharjan ◽  
Mim Lal Nakarmi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Single Photon ◽  
Excitation Power ◽  
Ultraviolet Region ◽  
Composition Analysis ◽  
Sapphire Crystal ◽  
Third Harmonic ◽  
X Ray ◽  
The Third ◽  
Deep Uv

ABSTRACTDeep UV photoluminescence (PL) spectroscopy was employed to study optical properties of a sapphire substrate sample. The sample was photo-excited by the third harmonic laser of a Ti:sapphire pulse laser at wavelength ~ 266 nm which is a below bandgap excitation. In the low temperature (12 K) PL measurement, we observed two sharp atomic-like emissions in the ultraviolet region with peaks at 3.361 eV and 3.315 eV with spectral line-width of 0.85 and 3.30 nm respectively, in the PL spectrum. We performed temperature and power-dependent PL measurements of the sample and observed that the emission peak positions did not change with changing excitation power and sample temperature. We also performed X-ray photoelectron spectroscopy for chemical composition analysis of the sample to explore the origin of the atomic-like emission that could be used for single photon sources for quantum information technology. We will discuss a possible electronic transition and its origin in sapphire.

scholarly journals Switching of the harmonic order in free-electron lasers by controlling the density modulation of an electron bunch

2018 ◽  
Vol 25 (5) ◽  
pp. 1317-1322 ◽  
Author(s):  
Norihiro Sei ◽  
Hiroshi Ogawa ◽  
QiKa Jia
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Extreme Ultraviolet ◽  
Free Electron Lasers ◽  
Harmonic Order ◽  
Third Harmonic ◽  
X Ray ◽  
The Third ◽  
Density Modulation ◽  
Higher Harmonic

It was demonstrated that harmonic order in free-electron laser (FEL) oscillations could be switched by adjusting the dispersive gap of the optical klystron ETLOK-III in the storage ring NIJI-IV. The effective gains for the fundamental and third-harmonic FEL oscillations were evaluated and it was confirmed that the FEL oscillated at the order of the harmonic with the higher effective gain. The ratio between the effective gain for the fundamental and that for the third harmonic was controlled by the dispersive gap. It was also demonstrated that a spectral measurement of the FEL-based Compton scattering X-ray beam was effective for directly observing the switching of the harmonic order. These results contribute to the development of higher-harmonic FEL oscillations suppressing the fundamental FEL oscillation in the extreme ultraviolet and X-ray regions.

Characterization on the Microstructures and Optical Performances of TiO2 Doped with Transition Metals

2014 ◽  
Vol 887-888 ◽  
pp. 388-394 ◽  
Author(s):  
Xin Hua Liu ◽  
Yi Deng ◽  
Yu Chuan Zhang ◽  
Yin Hang Zhou
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Transition Metal Ions ◽  
Ultraviolet Region ◽  
Visible Light Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Light Region ◽  
Cu Ions

The structures and optical performances of TiO2doped with 4thperiodic transition metal ions were investigated in this paper. The characterization results of X-ray photoelectron spectroscopy and X-ray diffraction showed that the transition metal ions existed in oxidative states, and composites formed because of the reaction between doped metal ions and TiO2. The absorption spectroscopy of TiO2doped with zinc was mainly in ultraviolet region, close to that of the pure TiO2. While for TiO2doped with other transition metal ions including V, Cr, Mn, Fe, Co, Ni and Cu ions, the absorption spectroscopies covered ultraviolet region and visible light region, much broader than that of the pure TiO2.

scholarly journals The Effects of Ti Additions and Deposition Parameters on the Structural and Mechanical Properties of Stainless Steel-Nitride Thin Films

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 329
Author(s):  
Faisal I. Alresheedi ◽  
James E. Krzanowski
Keyword(s):  
Stainless Steel ◽  
Photoelectron Spectroscopy ◽  
Lower Surface ◽  
Grain Structure ◽  
Composition Analysis ◽  
Transition Metal Nitrides ◽  
N Content ◽  
X Ray ◽  
Deposition Parameters ◽  
Stainless Steel Coatings

This study examines the structure and properties of stainless steel coatings deposited to incorporate large concentrations of nitrogen along with varying amounts of titanium. Deposition was carried out using magnetron co-sputtering of stainless steel and titanium from separate targets in a mixed Ar/N2 gas atmosphere. Composition analysis by X-ray photoelectron spectroscopy showed that while films with up to 4 at.% Ti exhibited little change in nitrogen content (compared to films deposited without Ti) and remained sub-stoichiometric with respect to N content. Films with 7–8 at.% Ti had a higher N level and further increasing the Ti level to 11–12 at.% resulted in stoichiometric N levels. X-ray diffraction showed that the films all had a nominally FCC structure with no additional phases. However, the peak locations for the (111) and (200) reflections indicated a distorted lattice characteristic of the S-phase, with calculated c/a values ranging from 1.007 to 1.033. The Ti additions, along with the corresponding increase in N content, helped reduce the extent of lattice distortion. The film microstructure of the higher (11–12 at.%) Ti films also showed higher density, lower surface roughness, and a finer grain structure. As a result, these films had a higher hardness compared to the sub-stoichiometric films, with hardness levels in the range of 18–23 GPa, typical of transition metal nitrides coatings.

Electrochemical and Spectroscopie Evaluation of Lithium Intercalation in Tailored Polymethacrylonitrile Carbons

1997 ◽  
Vol 496 ◽  
Author(s):  
Kevin R. Zavadil ◽  
Ronald A. Guidotti ◽  
William R. Even
Keyword(s):  
Photoelectron Spectroscopy ◽  
Bound States ◽  
Secondary Ion Mass Spectrometry ◽  
Surface Film ◽  
Lithium Ion ◽  
Irreversible Loss ◽  
X Ray ◽  
The Third ◽  
Secondary Ion ◽  
Voltammetric Measurements

AbstractDisordered polymethacrylonitrile (PMAN) carbon monoliths have been studied as potential tailored electrodes for lithium ion batteries. A combination of electrochemical and surface spectroscopie probes have been used to investigate irreversible loss mechanisms. Voltammetric measurements show that Li intercalates readily into the carbon at potentials IV positive of the reversible Li potential. The coulometric efficiency rises rapidly from 50% for the first potential cycle to greater than 85% for the third cycle, indicating that solvent decomposition is a self-limiting process. Surface film composition and thickness, as measured by x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS), does not vary substantially when compared to more ordered carbon surfaces. Li+ profiles are particularly useful in discriminating between the bound states of Li at the surface of solution permeable PMAN carbons.

XPS AND XPD ANALYSIS OF NITROGEN ADSORPTION ON THE Ti(0001) SURFACE

1997 ◽  
Vol 04 (06) ◽  
pp. 1309-1314 ◽  
Author(s):  
D. P. FRICKEL ◽  
M. V. KUZNETSOV ◽  
E. V. SHALAEVA
Keyword(s):  
Photoelectron Spectroscopy ◽  
Titanium Surface ◽  
Nitrogen Adsorption ◽  
Text Structure ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
The Third ◽  
Adsorption Temperature ◽  
Nearest Neighborhood ◽  
Kinetics Of

X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD) were used to examine the kinetics of nitrogen adsorption on the Ti(0001) surface at temperatures from 220 to 570 K and adsorption exposures from 0 to 1000 L. At the adsorption temperature T=300 K two chemically nonequivalent states of nitrogen were found: NI (1×1 lattice) localized in octapores between the first and second titanium monolayers and NII (presumably [Formula: see text] structure) on the titanium surface. The third nitrogen state, N0 , which is also localized on the surface but has unoccupied octapores in the nearest neighborhood, is observed with a decrease in the adsorption temperature to 220 K. A model of nitrogen interaction with the Ti(0001) surface in vacuum was proposed proceeding from the temperature dependence of the kinetic adsorption curves.

Surface composition analysis of HF vapour cleaned silicon by X-ray photoelectron spectroscopy

1991 ◽  
Vol 48-49 ◽  
pp. 178-184 ◽  
Author(s):  
A. Ermolieff ◽  
F. Martin ◽  
A. Amouroux ◽  
S. Marthon ◽  
J.F.M. Westendorp
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Composition Analysis ◽  
X Ray

scholarly journals Rapid Atmospheric Leaching of Chalcopyrite Using a Novel Reagent of Trichloroisocyanuric Acid

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1012
Author(s):  
Guobao Chen ◽  
Jiarui Sun ◽  
Hongying Yang ◽  
Pengcheng Ma ◽  
Shixiong Gao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Cyanuric Acid ◽  
Passivation Layer ◽  
Composition Analysis ◽  
Copper Extraction ◽  
Low Grade ◽  
X Ray ◽  
Atmospheric Leaching ◽  
Leaching Reaction ◽  
Trichloroisocyanuric Acid

With the decrease in high-grade chalcopyrite resources, the copper extraction from low-grade chalcopyrite has attracted more and more attention. However, the kinetic rates of chalcopyrite leaching with traditional oxidants are usually very slow due to the formation of the passivation layer. In this study, a novel reagent of chlorinated oxidant, trichloroisocyanuric acid (TCCA), was used to leach chalcopyrite for the first time. The experimental results showed that when the initial oxidant concentration for TCCA was 0.054 mol·L−1, the leaching temperature was kept at 55 °C, and the pH of the pulp was controlled at 1, the oxidation efficiency of Cu can reach above 90% in less than 30 min. Various analyses of chalcopyrite mineral ore and its oxidized residues, such as chemical composition analysis, X-ray diffraction analysis, scanning electron microscopy analysis and X-ray photoelectron spectroscopy, were conducted, respectively. No obvious passivation layer was found on the chalcopyrite surface, though the sulfur product can also be generated during the leaching. Reaction kinetic analysis results showed that the different influence of surface reaction and diffusion process on the dissolution of chalcopyrite is little due to the fast leaching speed. After calculation, the activation energy of the whole leaching reaction is 9.06 kJ·mol−1, much lower than that in other reports. The mechanism was also proposed that TCCA was hydrolyzed in the solution to form hypochlorous acid, which is the strong oxidant, and cyanuric acid, which prevents the formation of a passivation layer. The processing in this study is expected to be applied as a novel method for atmospheric leaching of chalcopyrite.

Surface Composition Analysis of HF Vapor Cleaned Silicon by X Ray Photoelectron Spectroscopy

1990 ◽  
Author(s):  
Anne ERMOLIEFF ◽  
F. MARTIN ◽  
A. AMOUROUX ◽  
S. MARTHON ◽  
J. F. M WESTENDORP
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Composition Analysis ◽  
X Ray
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