Development of a low-temperature photoelectron spectroscopy instrument using an electrospray ion source and a cryogenically controlled ion trap

2008 ◽  
Vol 79 (7) ◽  
pp. 073108 ◽  
Author(s):  
Xue-Bin Wang ◽  
Lai-Sheng Wang
Keyword(s):  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Ion Trap ◽  
Ion Source

scholarly journals Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Freeze Drying ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

Uniform Depth Profiling in X-ray Photoelectron Spectroscopy (Electron Spectroscopy for Chemical Analysis)

1978 ◽  
Vol 32 (2) ◽  
pp. 175-177 ◽  
Author(s):  
L. Bradley ◽  
Y. M. Bosworth ◽  
D. Briggs ◽  
V. A. Gibson ◽  
R. J. Oldman ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Auger Electron Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Depth Profiling ◽  
Ion Source ◽  
X Ray ◽  
Nitride Oxide ◽  
Silicon Device

The difficulties of nonuniform ion etching which hamper depth profiling by X-ray photoelectron spectroscopy (XPS) have been overcome by use of a mechanically scanned saddle-field ion source. The system and its calibration for uniformity are described, and its performance is illustrated by the depth profile of a Si3N4/SiO2/Si metal nitride oxide silicon device. This also allows the potential advantages of XPS profiling over Auger electron spectroscopy profiling to be discussed.

scholarly journals Synthesis of new Ln4(Al2O6F2)O2 (Ln = Sm, Eu, Gd) phases with a cuspidine-related structure

IUCrJ ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 128-135 ◽  
Author(s):  
Aroa Morán-Ruiz ◽  
Aritza Wain-Martin ◽  
Alodia Orera ◽  
María Luisa Sanjuán ◽  
Aitor Larrañaga ◽  
...  
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Raman Spectra ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Temperature Reaction ◽  
Rietveld Refinements ◽  
X Ray ◽  
Vinylidene Difluoride ◽  
Vacant Position

The first fluorination of the cuspidine-related phases of Ln4(Al2O7□)O2 (where Ln = Sm, Eu, Gd) is reported. A low-temperature reaction with poly(vinylidene difluoride) lead to the fluorine being substituted in place of oxygen and inserted into the vacant position between the dialuminate groups. X-ray photoelectron spectroscopy shows the presence of the F 1s photoelectron together with an increase in Al 2p and rare-earth 4d binding energies supporting F incorporation. Energy-dispersive X-ray spectroscopy analyses are consistent with the formula Ln4(Al2O6F2)O2, confirming that substitution of one oxygen by two fluoride atoms has been achieved. Rietveld refinements show an expansion in the cell upon fluorination and confirm that the incorporation of fluoride in the Ln4(Al2O7□)O2 structure results in changes in Al coordination from four to five. Thus, the isolated tetrahedral dialuminate Al2O7 groups are converted to chains of distorted square-based pyramids. These structural results are also discussed based on Raman spectra.

scholarly journals Low-Temperature Chemical Vapor Deposition Growth of MoS2 Nanodots and Their Raman and Photoluminescence Profiles

2021 ◽  
Vol 3 ◽  
Author(s):  
Larionette P. L. Mawlong ◽  
Ravi K. Biroju ◽  
P. K. Giri
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Substrate Temperature ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Flexible Substrate ◽  
Chemical Vapor ◽  
Structural Defects ◽  
Chemical Vapor Deposition Growth ◽  
Raman Modes

We report on the growth of an ordered array of MoS2 nanodots (lateral sizes in the range of ∼100–250 nm) by a thermal chemical vapor deposition (CVD) method directly onto SiO2 substrates at a relatively low substrate temperature (510–560°C). The temperature-dependent growth and evolution of MoS2 nanodots and the local environment of sulfur-induced structural defects and impurities were systematically investigated by field emission scanning electron microscopy, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques. At the substrate temperature of 560°C, we observed mostly few-layer MoS2, and at 510°C, multilayer MoS2 growth, as confirmed from the Raman line shape analysis. With reduced substrate temperature, the density of MoS2 nanodots decreases, and layer thickness increases. Raman studies show characteristic Raman modes of the crystalline MoS2 layer, along with two new Raman modes centered at ∼346 and ∼361 cm−1, which are associated with MoO2 and MoO3 phases, respectively. Room temperature photoluminescence (PL) studies revealed strong visible PL from MoS2 layers, which is strongly blue-shifted from the bulk MoS2 flakes. The strong visible emission centered at ∼ 658 nm signifies a free excitonic transition in the direct gap of single-layer MoS2. Position-dependent PL profiles show excellent uniformity of the MoS2 layers for samples grown at 540 and 560°C. These results are significant for the low-temperature CVD growth of a few-layer MoS2 dots with direct bandgap photoluminescence on a flexible substrate.

A Theoretical Investigation of the Kinetic Energy of Ions Trapped in a Radio-Frequency Hexapole Ion Trap

2002 ◽  
Vol 8 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Liam A. McDonnell ◽  
Anastassios E. Giannakopulos ◽  
Peter J. Derrick ◽  
Youri O. Tsybin ◽  
Per Håkansson
Keyword(s):  
Kinetic Energy ◽  
Radio Frequency ◽  
Space Charge ◽  
Free Path ◽  
Ion Trap ◽  
Mean Free Path ◽  
Ion Source ◽  
Average Kinetic Energy ◽  
Negative Consequences ◽  
Covalent Adducts

The kinetic energy dependence of ions trapped in a radio-frequency (RF) hexapole ion trap has been calculated as a function of space charge, mean free path, mass, RF potential and charge. The average kinetic energy of the ions was found to increase with increasing space charge, mean free path and the ion charge state. For a trapped ion in a given coulombic field, the mass of the ion and the amplitude of the applied RF potential did not affect the average kinetic energy. The consequences for multipole-storage-assisted dissociation (MSAD), in which ions are accumulated for prolonged periods of time in the multipole ion trap of an electrospray ion source, are discussed. As a result of radial stratification inside the ion trap, MSAD can lead to the preferential excitation of ions with larger m/z values. Such discrimination would have negative consequences for the detection of labile non-covalent adducts, which are normally detected at higher m/z values than their constituent species.

scholarly journals Nanosized V-Ce Oxides Supported on TiO2 as a Superior Catalyst for the Selective Catalytic Reduction of NO

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 202
Author(s):  
Long Lu ◽  
Xueman Wang ◽  
Chunhua Hu ◽  
Ying Liu ◽  
Xiongbo Chen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Redox Capacity ◽  
Scr Of No ◽  
Temperature Programmed

Nanosized V-Ce oxides supported on TiO2 (VCT) were prepared and utilized in the low-temperature selective catalytic reduction (SCR) of NO with NH3. Compared with the other V-Ce oxides-based catalysts supported on Al2O3, ZrO2, and ZSM-5, VCT showed the best SCR activity in a low-temperature range. The NOx conversion of 90% could be achieved at 220 °C. Characterizations including X-ray diffraction (XRD), scanning election micrograph (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption with NH3 (NH3-TPD), and temperature-programmed reduction with H2 (H2-TPR) showed that V1.05Ce1/TiO2 exhibited a good dispersion of V2O5, enrichment of surface Ce3+ and chemical-absorbed oxygen, and excellent redox capacity and acidity, which resulted in the best SCR performance at low temperature.

scholarly journals ITO/SiO2/ITO Structure on a Sapphire Substrate Using the Oxidation of Ultra-Thin Si Films as an Insulating Layer for One-Glass-Solution Capacitive Touch-Screen Panels

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 134 ◽  
Author(s):  
Shin Yong Joo ◽  
Chadrasekhar Loka ◽  
Young Woong Jo ◽  
Maddipatla Reddyprakash ◽  
Sung Whan Moon ◽  
...  
Keyword(s):  
Low Temperature ◽  
Sapphire Substrate ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Touch Screen ◽  
Sio2 Film ◽  
Silicon Films ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Si Films

The SiO2 generated by low-temperature oxidation of ultra-thin metallic silicon (thickness = 50 nm) film was evaluated for implementation in one-glass-solution capacitive touch-screen panels (OGS-TSPs) on sapphire-based substrates. Our results show that the silicon films oxidized at 823 K exhibited the highest visible transmittance about 91% at 550 nm, compared to ~72% transmittance of the as-deposited silicon films which were deposited at room temperature. Additionally, the annealed films exhibited a more uniform, dense, and smooth surface microstructure than that of the as-deposited Si films. X-ray photoelectron spectroscopy (XPS) results revealed that the low-temperature oxidation of Si films at 823 K yielded SiO2. Furthermore, when the insulating SiO2 film obtained by low-temperature oxidation was sandwiched between two indium tin oxide (ITO) layers (ITO/SiO2/ITO) on a sapphire substrate, the SiO2 film resulted in the dielectric strength of approximately 3 MV/cm. In addition, the highest optical transmittance obtained by the ITO/SiO2/ITO films is about 88.3%. The change in capacitance of the ITO/SiO2/ITO structure was approximately 3.2 pF, which indicates the possibility of implementation in capacitive touch-screen panel devices.

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