Dissociative chemisorption of O2 on Agn and Agn−1Ir (n = 3–26) clusters: a first-principle study

2020 ◽  
Vol 22 (16) ◽  
pp. 9053-9066
Author(s):  
Chuangchuang Wang ◽  
Yongpeng Yang ◽  
Xiaojing Liu ◽  
Yuanjie Li ◽  
Dandan Song ◽  
...  
Keyword(s):  
Reaction Rates ◽  
First Principle ◽  
Dissociative Chemisorption ◽  
Dopant Effect

Lower dissociation barriers and higher reaction rates of O2 on doped Agn−1Ir clusters, and a gradually weakened dopant effect.

scholarly journals Clustering and alpha-capture reaction rates from first-principle structure calculations for nucleosynthesis

2018 ◽  
Author(s):  
A. C. Dreyfuss ◽  
K. D. Launey ◽  
J. E. Escher ◽  
R. B. Baker ◽  
J. P. Draayer ◽  
...  
Keyword(s):  
Reaction Rates ◽  
First Principle ◽  
Capture Reaction ◽  
Structure Calculations ◽  
Alpha Capture

GAS-PHASE CHEMISTRY OF MOLYBDENUM CLUSTERS

1996 ◽  
Vol 03 (01) ◽  
pp. 675-678 ◽  
Author(s):  
D.M. RAYNER ◽  
L. LIAN ◽  
S.A. MITCHELL ◽  
P.A. HACKETT
Keyword(s):  
Gas Phase ◽  
Flow Reactor ◽  
Molecular Nitrogen ◽  
Negative Temperature ◽  
Bound State ◽  
Reaction Rates ◽  
Laser Vaporization ◽  
Dissociative Chemisorption ◽  
Kinetic Measurements ◽  
Molybdenum Clusters

The kinetics of reactions of molybdenum clusters, Mo n, n=1–25, in the pressure range 0.4–4 Torr, and temperature range 270–380 K, have been investigated using a large-bore, He-buffered, fast-flow reactor equipped with a laser-vaporization source for the production of clusters. The reactor is designed to make kinetic measurements on neutral metal clusters in the gas phase under well-defined pressures and temperatures. We discuss a new version of the instrument in which LIF techniques, used previously to monitor atoms and dimers, are replaced by laser ionization, time-of-flight mass spectrometry (TOFMS) in order to monitor larger clusters. The new version of the reactor has been tested against known reactions of Ti atoms. Examples of the reactor’s performance are taken from studies performed on Mon cluster reactivity. In particular we summarize some results on the dissociative chemisorption of molecular nitrogen, where large cluster-size effects are found. In some cases a negative-temperature dependence of the kinetics indicates the involvement of a precursor bound state and leads to conclusions concerning the shape of the potential-energy surface and how subtle changes associated with the cluster’s geometric structure might profoundly alter reaction rates.

SEM analysis of the change in the reaction rates with deposit structures in the copper-iron cementation system

1978 ◽  
Vol 36 (1) ◽  
pp. 456-457
Author(s):  
V. Annamalai ◽  
L.E. Murr
Keyword(s):  
Structural Characteristics ◽  
Secondary Electron Emission ◽  
Copper Deposit ◽  
Reaction Rates ◽  
Sem Analysis ◽  
Experimental Conditions ◽  
Major Drawback ◽  
Emission Mode ◽  
Scrap Iron ◽  
Image Position

Economical recovery of copper metal from leach liquors has been carried out by the simple process of cementing copper onto a suitable substrate metal, such as scrap-iron, since the 16th century. The process has, however, a major drawback of consuming more iron than stoichiometrically needed by the reaction.Therefore, many research groups started looking into the process more closely. Though it is accepted that the structural characteristics of the resultant copper deposit cause changes in reaction rates for various experimental conditions, not many systems have been systematically investigated. This paper examines the deposit structures and the kinetic data, and explains the correlations between them.A simple cementation cell along with rotating discs of pure iron (99.9%) were employed in this study to obtain the kinetic results The resultant copper deposits were studied in a Hitachi Perkin-Elmer HHS-2R scanning electron microscope operated at 25kV in the secondary electron emission mode.

The Effects of Nitrogen on Electrical and Structural Properties in TaSixNy/SiO2/p-Si MOS Capacitors

2002 ◽  
Vol 716 ◽  
Author(s):  
You-Seok Suh ◽  
Greg Heuss ◽  
Jae-Hoon Lee ◽  
Veena Misra
Keyword(s):  
Structural Properties ◽  
Electron Spectroscopy ◽  
Oxygen Diffusion ◽  
Gate Dielectric ◽  
Barrier Properties ◽  
Reaction Rates ◽  
Cross Sectional ◽  
Mos Capacitors ◽  
Transmission Electron ◽  
Thermal Stability Of

AbstractIn this work, we report the effects of nitrogen on electrical and structural properties in TaSixNy /SiO2/p-Si MOS capacitors. TaSixNy films with various compositions were deposited by reactive sputtering of TaSi2 or by co-sputtering of Ta and Si targets in argon and nitrogen ambient. TaSixNy films were characterized by Rutherford backscattering spectroscopy and Auger electron spectroscopy. It was found that the workfunction of TaSixNy (Si>Ta) with varying N contents ranges from 4.2 to 4.3 eV. Cross-sectional transmission electron microscopy shows no indication of interfacial reaction or crystallization in TaSixNy on SiO2, resulting in no significant increase of leakage current in the capacitor during annealing. It is believed that nitrogen retards reaction rates and improves the chemical-thermal stability of the gate-dielectric interface and oxygen diffusion barrier properties.

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