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Herring-Captain, Janine; Grieves, G. A.; Alexandrov, Alex; Sieger, M. T.; Chen, Haiyan; Orlando, Thomas M.

doi:10.1103/physrevb.72.035431

Cited by 35 publications

(36 citation statements)

References 58 publications

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“…Above 100 K, the mobility of defects within the ice lattice increases resulting in the reorientation and rearrangement of interfacial molecules and increased inter-molecular spacing. These effects collectively result in increased excited state lifetimes and higher dissociation probabilities of H 2 O molecules Herring-Captain et al 2005). Thus the CO 2 formation is enhanced by the increasing availability of radicals from H 2 O.…”

Section: Co/co 2 Formation At the Buried Interfacementioning

confidence: 95%

Vacuum Ultraviolet Photon-Stimulated Oxidation of Buried Ice: Graphite Grain Interfaces

Shi

Grieves

Orlando

2015

ApJ

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The vacuum ultraviolet (VUV) synthesis of CO and CO 2 on ice-coated graphite and isotopic labeled 13 C graphite has been examined for temperatures between 40 and 120 K. The results show that CO and CO 2 can be formed at the buried ice:graphite interface with Lyα photon irradiation via thereaction of radicals (O and OH) produced by direct photodissociation and the dissociative electron attachment of the interfacial water molecules. The synthesized CO and CO 2 molecules can desorb in hot photon-dominated regions and arelost to space when ice coated carbonaceous dust grains cycle within the protoplanetary disks. Thus, the nonthermal formation of CO and CO 2 at the buried ice:grain interface by VUV photons may help regulate the carbon inventory during the early stage of planet formation. This may contribute to the carbon deficits in our solar systemand suggests that a universal carbon deficit gradient may be expected within astrophysical bodies surrounding center stars.

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Section: Co/co 2 Formation At the Buried Interfacementioning

confidence: 95%

Vacuum Ultraviolet Photon-Stimulated Oxidation of Buried Ice: Graphite Grain Interfaces

Shi

Grieves

Orlando

2015

ApJ

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“…A more detailed description of the electronic structure of water and the mechanisms of H þ , H 2 þ , and H þ (H 2 O) n=1À7 desorption from water can be found elsewhere. 20,23 Calculations and photoemission data show the electronic structure of condensed ice retains much of The Journal of Physical Chemistry A ARTICLE the gas phase character with some broadening and minor shifting of the energy levels. The largest change in the condensed phase occurs in the a 1 levels that are significantly broadened (compared to the 1b 1 and 1b 2 levels) and are most affected by hydrogen bonding.…”

Section: Iva Mechanisms For Cation Esdmentioning

confidence: 98%

“…A detailed description of the cation yields from pristine ice can be found elsewhere. 23 Briefly, the cation yield is dominated by H þ with a much less H 2 þ , and an even smaller yield of H þ (H 2 O) n . The cluster yield from PASW is the highest and it is typically 5À6 times larger than for CI, and about 2À3 times larger than for ASW.…”

Section: Iiia Esd Of Cations From Ice Surfaces Containingmentioning

confidence: 99%

“…Since levels with a 1 character are sensitive to the local bonding environment, we can use the proton yields to gather information about the local geometry and dynamic response of the ice surface. 23 At low dosing temperatures, the random orientation of the surface water molecules leads to a low proton yield for PASW compared to CI most likely because the proton undergoes reactive scattering across the ice surface or into the bulk. 24 As the temperature increases, the degree of coupling between water molecules decreases while the number of dangling bonds and mobility of surface water molecules increases.…”

Section: Iva Mechanisms For Cation Esdmentioning

confidence: 99%

“…The cluster yield from PASW is the highest and it is typically 5À6 times larger than for CI, and about 2À3 times larger than for ASW. 23 A very interesting and dramatic change in the cation yields occurs due to the presence of small amounts of HCl. 22 This change can be seen in Figure 1 where the dashed gray lines represent the ESD yields after a dose of ∼0.1 ML of HCl.…”

Section: Iiia Esd Of Cations From Ice Surfaces Containingmentioning

confidence: 99%

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Probing the Interaction of Hydrogen Chloride with Low-Temperature Water Ice Surfaces Using Thermal and Electron-Stimulated Desorption

et al. 2011

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The interaction and autoionization of HCl on low-temperature (80-140 K) water ice surfaces has been studied using low-energy (5-250 eV) electron-stimulated desorption (ESD) and temperature programmed desorption (TPD). There is a reduction of H(+) and H(2)(+) and a concomitant increase in H(+)(H(2)O)(n=1-7) ESD yields due to the presence of submonolayer quantities of HCl. These changes are consistent with HCl induced reduction of dangling bonds required for H(+) and H(2)(+) ESD and increased hole localization necessary for H(+)(H(2)O)(n=1-7) ESD. For low coverages, this can involve nonactivated autoionization of HCl, even at temperatures as low as 80 K; well below those typical of polar stratospheric cloud particles. The uptake and autoionization of HCl is supported by TPD studies which show that for HCl doses ≤0.5 ± 0.2 ML (ML = monolayer) at 110 K, desorption of HCl begins at 115 K and peaks at 180 K. The former is associated with adsorption of a small amount of molecular HCl and is strongly dependent on the annealing history of the ice. The latter peak at 180 K is commensurate with desorption of HCl via recombinative desorption of solvated separated ion pairs. The activation energy for second-order desorption of HCl initially in the ionized state is 43 ± 2 kJ/mol. This is close to the zero-order activation energy for ice desorption.

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Chemistry in Water Ices: From Fundamentals to Planetary Applications

Gudipati

Cooper

2012

The Science of Solar System Ices

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Low-energy(5–250eV)electron-stimulated desorption ofH+,

Cited by 35 publications

References 58 publications

Vacuum Ultraviolet Photon-Stimulated Oxidation of Buried Ice: Graphite Grain Interfaces

Vacuum Ultraviolet Photon-Stimulated Oxidation of Buried Ice: Graphite Grain Interfaces

Probing the Interaction of Hydrogen Chloride with Low-Temperature Water Ice Surfaces Using Thermal and Electron-Stimulated Desorption

Chemistry in Water Ices: From Fundamentals to Planetary Applications

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