AROMATIC MOLECULAR JUNCTIONS WITH INERT GASES AS ALLIGATOR CLIPS

2012 ◽  
Vol 04 (04) ◽  
pp. 1250015 ◽  
Author(s):  
RUPAN PREET KAUR ◽  
RAVINDER SINGH SAWHNEY ◽  
DERICK ENGLES
Keyword(s):  
Noble Gas ◽  
Inert Gases ◽  
Nanometer Scale ◽  
Gold Electrodes ◽  
Transport Parameters ◽  
Anthracene Molecule ◽  
Nonequilibrium Green Function ◽  
Semi Empirical ◽  
Helium Neon ◽  
Maximum Conductance

In this research paper, we examined the effect of placing the elements of Group 0 as alligator clips with Anthracene molecule binding gold electrodes on the nanometer scale using Extended Huckle Theory (EHT) based semi-empirical model. The electron transport parameters i.e., I-V curves, Conductance-Voltage curves and transmission spectrum were investigated through Anthracene molecule by buffering it between two semi-infinite gold electrodes but via different alligator clips-Helium, Neon, Argon, Krypton, Xenon and Radon, all from Noble gas group or group-0 under finite bias voltages within Keldysh's nonequilibrium green function formalism (NEGF). The simulated results revealed that the Xenon and Radon showed maximum conduction whereas Krypton, Neon, Helium and Argon showed least. The maximum conductance of 0.62G0 and 70.4 μA current was exhibited by Xenon and thus affirmed to be the most optimal alligator clip amongst noble gases at nanometre scale.

Proliferating conduction by isomerism

2015 ◽  
Vol 04 (04) ◽  
pp. 1550024 ◽  
Author(s):  
Rupan Preet Kaur ◽  
Ravinder Singh Sawhney ◽  
Derick Engles
Keyword(s):  
Electron Transport ◽  
Electrical Conduction ◽  
Empirical Model ◽  
Research Work ◽  
Gold Electrodes ◽  
Transport Parameters ◽  
Hückel Theory ◽  
Anthracene Molecule ◽  
Semi Empirical ◽  
Maximum Conductance

The electrical conduction of isomers of anthracene molecule attached between two semi-infinite gold electrodes was simulated using extended Huckel theory (EHT)-based on semi-empirical model in this research work. The electron transport parameters were examined in two epochs by buffering anthracene and its isomer phenanthrene alternatively between gold electrodes using sulphur as an alligator clip, under variegated bias voltages. Differential NDR effect was observed in both the cases but phenanthrene exhibited more linear I–V curve than its counterpart, anthracene. The simulated results discovered phenanthrene as a better candidate than anthracene towards contributing to electrical conduction in molecular junctions. Phenanthrene reported maximum conductance of 0.74G0 whereas anthracene exhibited 0.03[Formula: see text]G0 at 0.8[Formula: see text]V.

Augmenting Molecular Junctions with Different Transition Metal Contacts

2013 ◽  
Vol 05 (02) ◽  
pp. 1350009 ◽  
Author(s):  
Rupan Preet Kaur ◽  
Ravinder Singh Sawhney ◽  
Derick Engles
Keyword(s):  
Electron Transport ◽  
Nanometer Scale ◽  
Metal Contacts ◽  
Transport Parameters ◽  
Empirical Modelling ◽  
Copper Electrodes ◽  
Electron Transport Properties ◽  
Semi Empirical ◽  
Maximum Conductance ◽  
Modelling Approach

In this research paper, the effect of the material of electrodes at the nanometer scale was elucidated towards measuring the electron transport properties of a single molecular junction comprising of anthracenedithiol molecule (ADT) stringed to two semi-infinite metallic electrodes using Extended Huckle Theory (EHT)-based semi-empirical modelling approach. The electron transport parameters i.e., I–V curves, Conductance-Voltage curves and transmission spectrum were investigated through ADT molecule by buffering it between different electrodes composed of rhodium, palladium, nickel and copper, all from transition metals series, under finite bias voltages within Keldysh's non equilibrium green function formulism (NEGF). The simulated results revealed that the copper electrodes showed maximum conduction whereas palladium showed least. The maximum conductance of 0.82 G0 and 43 μA current was exhibited by copper and thus affirmed to be the most effective electrode at nanometre scale when compared with other electrodes viz. nickel, rhodium and palladium.

The absolute photoionization cross sections of helium, neon, argon and krypton in the extreme vacuum ultraviolet region of the spectrum

1976 ◽  
Vol 349 (1658) ◽  
pp. 397-421 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Vacuum Ultraviolet ◽  
Theoretical Calculations ◽  
Critical Evaluation ◽  
Inert Gases ◽  
Ultraviolet Region ◽  
Section Data ◽  
Wide Range ◽  
Helium Neon

An experiment has been set up at the Daresbury Synchrotron Radiation Facility to make absolute absorption cross section measurements over a wide range of photon energies. New data are reported for helium, neon, argon and krypton over the range 340-40 Å which are believed to be reliable to ± 5%. A critical evaluation of published cross section data has been carried out to produce best value data from the ionization thresholds throughout the vacuum ultraviolet and X-ray region. Agreement with theoretical calculations on helium is demonstrated to be within ± 2-3% from threshold down to the double ionization threshold at 79 eV. Comparison with recent calculations of photoionization cross sections has shown that the effect of electron correlations is significant for the heavier inert gases. Contrary to previous claims, the position of the M shell maximum in krypton is located at 184 + 10 eV in good agreement with r. p. a. e. calculations. Oscillator strength sum rules have been examined and their moments calculated. Discrepancies developing towards the heavier inert gases suggests a decrease in polarizabilities and other atomic factors from those predicted by Hartree-Fock calculations.

On Noble Gas Anomalies in the Great Namaqualand Troilite

1968 ◽  
Vol 23 (9) ◽  
pp. 1266-1271 ◽  
Author(s):  
E. C. Alexander ◽  
J. H. Bennett ◽  
O. K. Manuel
Keyword(s):  
Neutron Activation ◽  
Isotopic Composition ◽  
Neutron Capture ◽  
Noble Gases ◽  
Noble Gas ◽  
Helium Neon

The abundances and isotopic composition of the stable noble gases were measured in a troilite nodule from the Great Namaqualand fine octahedrite. Helium, neon and argon show a significant spallation component. The major anomalies in krypton and xenon are from neutron capture on selenium and tellurium and from the decay of extinct I129. The abundances of tellurium, iodine and uranium in the troilite were determined by neutron activation analyses and compared with the xenon anomalies. The results indicate that part of the excess Xe129 is from neutron capture on tellurium and the remainder is due to the retention of radiogenic Xe129 from the decay of extinct I129, about 200 million years after an initial I129/I127 = 3 × 10-3.

scholarly journals NOBLE GAS SOLUBILITY IN SUPER-CRITICAL WATER: IMPLICATIONS FOR INERT GAS STUDIES AND GEOCHRONOLOGY

1984 ◽  
Vol 23 (4) ◽  
pp. 483-490
Author(s):  
J. G. Mitchell ◽  
D. J. Terrell
Keyword(s):  
Low Temperatures ◽  
Volume Diffusion ◽  
Noble Gas ◽  
Inert Gases ◽  
Inert Gas ◽  
Gas Solubility ◽  
Transport Medium

Inert gases will ideally exhibit infinite miscibility with super-critical water.  The implications of this phenomenon are discussed in the context of the resetting of the K-Ar system during regional metamorhism, and emplacement of granites.  Inert gas abundances in oceanfloor rocks and shales may also be interpreted as a consequence (at least in part) of partioning between water and silicate phases in which the light inert gases are preferentially taken up in water.  The funtion of super-critical water as a transport medium for inert gases offers an important alternative to the unlikely process of volume diffusion at low temperatures.

Noble Gases: A Record of Earth's Evolution and Mantle Dynamics

2019 ◽  
Vol 47 (1) ◽  
pp. 389-419 ◽  
Author(s):  
Sujoy Mukhopadhyay ◽  
Rita Parai
Keyword(s):  
Noble Gases ◽  
Noble Gas ◽  
Isotopic Ratios ◽  
Mantle Structure ◽  
Mantle Dynamics ◽  
Mid Ocean Ridge ◽  
Giant Impacts ◽  
Ocean Ridge ◽  
Helium Neon

Noble gases have played a key role in our understanding of the origin of Earth's volatiles, mantle structure, and long-term degassing of the mantle. Here we synthesize new insights into these topics gained from high-precision noble gas data. Our analysis reveals new constraints on the origin of the terrestrial atmosphere, the presence of nebular neon but chondritic krypton and xenon in the mantle, and a memory of multiple giant impacts during accretion. Furthermore, the reservoir supplying primordial noble gases to plumes appears to be distinct from the mid-ocean ridge basalt (MORB) reservoir since at least 4.45 Ga. While differences between the MORB mantle and plume mantle cannot be explained solely by recycling of atmospheric volatiles, injection and incorporation of atmospheric-derived noble gases into both mantle reservoirs occurred over Earth history. In the MORB mantle, the atmospheric-derived noble gases are observed to be heterogeneously distributed, reflecting inefficient mixing even within the vigorously convecting MORB mantle. ▪ Primordial noble gases in the atmosphere were largely derived from planetesimals delivered after the Moon-forming giant impact. ▪ Heterogeneities dating back to Earth's accretion are preserved in the present-day mantle. ▪ Mid-ocean ridge basalts and plume xenon isotopic ratios cannot be related by differential degassing or differential incorporation of recycled atmospheric volatiles. ▪ Differences in mid-ocean ridge basalts and plume radiogenic helium, neon, and argon ratios can be explained through the lens of differential long-term degassing.

Positron lifetime spectra for gases

1982 ◽  
Vol 60 (4) ◽  
pp. 503-516 ◽  
Author(s):  
G. R. Heyland ◽  
M. Charlton ◽  
T. C. Griffith ◽  
G. L. Wright
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Inert Gases ◽  
Gas Density ◽  
Molecular Gases ◽  
Free Positron ◽  
To Receive ◽  
Helium Neon ◽  
Limiting Value ◽  
Good Agreement

Recent observations on the lifetime spectra for gases are presented and discussed. There is little to report on the inert gases helium, neon, and argon and the spectra for these gases are thought to be understood. New lifetime data for krypton and xenon have revealed two fast components which, although probably connected with the low positronium fractions for these gases, have yet to receive a satisfactory interpretation.The polarized orbital calculations for Zeff's and momentum transfer cross sections for all the inert gases by the York group are now complete and are generally in good agreement with experiment.For the molecular gases some information on rotational excitation cross sections has been obtained from thermalization times for nitrogen, hydrogen, and deuterium. In general, the [Formula: see text] parameter is dependant on gas density and temperature with some gases showing a pronounced maximum in the density dependance. The gases C3H8, C4H10, and CH3Cl have very large values of [Formula: see text] which indicate localization or capture of the positron by one or more molecules. These three gases exhibit a maximum in the instantaneous decay rate of the "free" positron component at low densities from which a "capture" cross section can be estimated.The positronium fraction, F, generally increases with the gas density, usually approaching a limiting value asymptotically, but for nitrogen this density dependance has a maximum at ~ 140 amagat. No satisfactory explanation has been offered for this behaviour.Positronium formation cross sections for several gases have been deduced from measurements of the variation of F with the concentration of the gas in helium. These cross sections are similar in magnitude to those deduced from the total cross section beam measurements.

Sign in / Sign up

Export Citation Format

Share Document