A new time-of-flight instrument capable of in situ and real-time studies of plasma-treated surfaces

Vacuum ◽  
2006 ◽  
Vol 81 (2) ◽  
pp. 196-201 ◽  
Author(s):  
F. Gou ◽  
M.A. Gleeson ◽  
J. Villette ◽  
A.W. Kleyn
Keyword(s):  
Real Time ◽  
Time Of Flight ◽  
New Time

scholarly journals In Situ, Real-Time Analysis of the Growth of Ferroelectric and Conductive Oxide Heterostructures by a New Time-of-Flight Pulsed Ion Beam Surface Analysis Technique

1994 ◽  
Vol 341 ◽  
Author(s):  
Orlando Auciello ◽  
A. R. Krauss ◽  
Y. Lin ◽  
R. P. H. Chang ◽  
D. M. Gruen
Keyword(s):  
Real Time ◽  
Surface Segregation ◽  
Ion Beam ◽  
Time Of Flight ◽  
Ion Scattering ◽  
Real Time Analysis ◽  
Analysis Technique ◽  
Conductive Oxide ◽  
New Time

AbstractA new time-of-flight ion scattering and recoil spectroscopy (TOF-ISARS) technique has been developed and is now used to perform in situ, real-time analysis of ferroelectric and conductive oxide layers during growth. Initial results presented here show various major effects, namely: (a) RuO2 films on MgO substrates appear to be terminated in O atoms on the top layer located in between Ru atoms lying in the layer underneath (This effect may have major implications for the explanation of the elimination of polarization fatigue demonstrated for RuO2/PZT/RuO2 heterostructure capacitors); (b) deposition of a Ru monolayer on top of a Pb monolayer results in surface segregation of Pb until a complete Pb layer develops over the Ru monolayer; and (c) a Pb/Zr/Ti layered structure yields a top Pb layer with first evidence of the existence of Pb vacancies, which also may have major implications in relation to the electrical characteristics of PZT-based capacitors.

scholarly journals In Situ, Real-Time Studies of Film Growth Processes Using Ion Scattering and Direct Recoil Spectroscopy Techniques

1999 ◽  
Vol 569 ◽  
Author(s):  
V.S. Smentkowskiv ◽  
A. R. Krauss ◽  
O. Auciello ◽  
J. Im ◽  
D.M. Gruen ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Spectroscopy ◽  
Film Growth ◽  
Ion Beam ◽  
Time Of Flight ◽  
Analytical Techniques ◽  
Surface Species ◽  
Ion Scattering ◽  
Growth Processes

ABSTRACTTime-of-flight ion scattering and recoil spectroscopy (TOF-ISARS) enables the characterization of the composition and structure of surfaces with 1–2 monolayer specificity. It will be shown that surface analysis is possible at ambient pressures greater than 3 mTorr using TOF-ISARS techniques; allowing for real-time, in situ studies of film growth processes. TOF-ISARS comprises three analytical techniques: ion scattering spectroscopy (ISS), which detects the backscattered primary ion beam; direct recoil spectroscopy (DRS), which detects the surface species recoiled into the forward scattering direction; and mass spectroscopy of recoiled ions (MSRI), which is a variant of DRS capable of isotopic resolution for all surface species - including H and He. The advantages and limitations of each of these techniques will be discussed.The use of the three TOF-ISARS methods for real-time, in situ film growth studies at high ambient pressures will be illustrated. It will be shown that MSRI analysis is possible during sputter deposition. It will be also be demonstrated that the analyzer used for MSRI can also be used for time of flight secondary ion mass spectroscopy (TOF-SIMS) under high vacuum conditions. The use of a single analyzer to perform the complimentary surface analytical techniques of MSRI and SIMS is unique. The dual functionality of the MSRI analyzer provides surface information not obtained when either MSRI or SIMS is used independently.

Single-Photon Ionization, In Situ Optical Diagnostic Of Molecular Beam Epitaxial Growth Of GaAs

1995 ◽  
Vol 406 ◽  
Author(s):  
Adina K. Ott ◽  
Sean M. Casey ◽  
April L. Alstrin ◽  
Stephen R. Leone
Keyword(s):  
Mass Spectrometry ◽  
Real Time ◽  
Molecular Beam ◽  
Single Photon ◽  
Surface Reactions ◽  
Time Of Flight ◽  
Single Photon Ionization ◽  
Flight Mass Spectrometry ◽  
Photon Ionization

AbstractSingle-photon ionization time-of-flight mass spectrometry (SPI-TOFMS) is used in situ to monitor desorbing species and surface reactions during molecular beam epitaxy (MBE) of GaAs. In this method, the 1064 nm fundamental output of a Nd:YAG laser is tripled twice to produce 118 nm (10.5 eV) photons. The pulsed light is passed in front of a growing substrate, giving gaseous scattered molecules sufficient energy to ionize, but not fragment, them. Ionized species are detected with time-of-flight mass spectrometry. Arrangement of the experiment also allows for simultaneous real time monitoring with reflection high-energy electron diffraction (RHEED).Mass spectra are examined and analyzed to quantify fluxes and relative ionization cross sections of growth species. The real time behavior of arsenic and gallium mass signals during epitaxy is presented as a function of substrate temperature and incident gallium flux. Surface reactions are proposed to elucidate mechanisms of arsenic incorporation and compared to measured RHEED results.

Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

2020 ◽  
Author(s):  
Feifei Jia ◽  
Jie Wang ◽  
Yanyan Zhang ◽  
Qun Luo ◽  
Luyu Qi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Time Of Flight ◽  
E Coli ◽  
Tof Sims ◽  
Ion Mass Spectrometry ◽  
Chemical Tags ◽  
Secondary Ion

<p></p><p><i>In situ</i> visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for <i>in situ </i>visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.</p><p></p>

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

Flat Flexible Thin Milli-electrode Array for Real-time in situ Water Quality Monitoring in Distribution Systems

2017 ◽  
Vol 2017 (4) ◽  
pp. 5598-5617
Author(s):  
Zhiheng Xu ◽  
Wangchi Zhou ◽  
Qiuchen Dong ◽  
Yan Li ◽  
Dingyi Cai ◽  
...  
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Distribution Systems ◽  
Electrode Array ◽  
Water Quality Monitoring ◽  
Quality Monitoring

scholarly journals Underground Microseismic Event Monitoring and Localization within Sensor Networks

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2830
Author(s):  
Sili Wang ◽  
Mark P. Panning ◽  
Steven D. Vance ◽  
Wenzhan Song
Keyword(s):  
Sensor Networks ◽  
Real Time ◽  
Information Needs ◽  
Localization Algorithm ◽  
Distributed Sensors ◽  
Distributed Sensor ◽  
Microseismic Events ◽  
The Stability ◽  
Stability And Accuracy

Locating underground microseismic events is important for monitoring subsurface activity and understanding the planetary subsurface evolution. Due to bandwidth limitations, especially in applications involving planetarily-distributed sensor networks, networks should be designed to perform the localization algorithm in-situ, so that only the source location information needs to be sent out, not the raw data. In this paper, we propose a decentralized Gaussian beam time-reverse imaging (GB-TRI) algorithm that can be incorporated to the distributed sensors to detect and locate underground microseismic events with reduced usage of computational resources and communication bandwidth of the network. After the in-situ distributed computation, the final real-time location result is generated and delivered. We used a real-time simulation platform to test the performance of the system. We also evaluated the stability and accuracy of our proposed GB-TRI localization algorithm using extensive experiments and tests.

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