Rutherford Backscattering to Study the Near-Surface Region of Volatile Liquids and Solids

Krieger, Ulrich K.; Huthwelker, Thomas; Daniel, Christian; Weers, U.; Peter, Thomas; Lanford, W. A.

doi:10.1126/science.1066654

Cited by 22 publications

(34 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The significant effect of HX deposition on R ev from ice may also be seen in HeNe interferograms shown in Fig. 4 and summarized in Table 3, and has been observed in two other studies of the condensed phase, one for HBr (Hudson et al, 2001), the other for HCl (Krieger et al, 2002). Our values for HBr are consistent with those in the literature (Hudson et al, 2001) and may lead to a surprising increase of the lifetime for an ice particle.…”

Section: Discussion and Atmospheric Implicationssupporting

confidence: 81%

The rate of water vapor evaporation from ice substrates in the presence of HCl and HBr: implications for the lifetime of atmospheric ice particles

2003

View full text Add to dashboard Cite

Abstract.Using a multidiagnostic approach the rate R ev [molec cm −3 s −1 ] or flux J ev [molec cm −2 s −1 ] of evaporation of H 2 O and its corresponding rate constant for condensation, k cond [s −1 ], on a 1 µm thick ice film have been studied in the temperature range 190 to 240 K as well as in the presence of small amounts of HCl and HBr that left the vapor pressure of H 2 O on ice unchanged. The resulting Arrhenius expressions for pure ice are J ev = 1.6 · 10 28±1 · expHCl mole fraction in the range 3.2 · 10 −5 − 6.4 · 10 −3 :, and a HBr mole fraction smaller than 6.4 · 10 −3 : J ev = 7.4 · 10 25±1 · expThe small negative activation energy for H 2 O condensation on ice points to a precursor mechanism. The corresponding enthalpy of sublimation is H subl = E ev − E cond = 11.9 ± 2.7 kcal mol −1 , H subl = 11.2 ± 2.8 kcal mol −1 , and H subl = 11.7 ± 2.8 kcal mol −1 whose values are identical within experimental uncertainty to the accepted literature value of 12.3 kcal mol −1 . Interferometric data at 633 nm and FTIR absorption spectra in transmission support the kinetic results. The data are consistent with a significant lifetime enhancement for HCl-and HBr-contaminated ice particles by a factor of 3-6 and 10-20, respectively, for submonolayer coverages of HX once the fraction of the ice not contaminated by HX has evaporated.

show abstract

Section: Discussion and Atmospheric Implicationssupporting

confidence: 81%

The rate of water vapor evaporation from ice substrates in the presence of HCl and HBr: implications for the lifetime of atmospheric ice particles

2003

View full text Add to dashboard Cite

show abstract

“…In an RBS experiment, He 2+ ions are shot into ice and the energy spectrum of the backscattered ions is a direct measure of the depth profile of the impurities in ice. It has been demonstrated that this technique can be used to follow the diffusion of HBr into ice in situ at HBr vapour pressures in the stability domain of ice and with a depth resolution of some 100 nm Krieger et al, 2002). In these studies the ice sample was not a well-defined single crystal as in the studies by Domine (1997, 1998) and Barret et al (2011b).…”

Section: Diffusion Of Impurities In the Ice Crystalmentioning

confidence: 71%

A review of air–ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow

et al. 2014

View full text Add to dashboard Cite

Abstract. Snow in the environment acts as a host to rich chemistry and provides a matrix for physical exchange of contaminants within the ecosystem. The goal of this review is to summarise the current state of knowledge of physical processes and chemical reactivity in surface snow with relevance to polar regions. It focuses on a description of impurities in distinct compartments present in surface snow, such as snow crystals, grain boundaries, crystal surfaces, and liquid parts. It emphasises the microscopic description of the ice surface and its link with the environment. Distinct differences between the disordered air–ice interface, often termed quasi-liquid layer, and a liquid phase are highlighted. The reactivity in these different compartments of surface snow is discussed using many experimental studies, simulations, and selected snow models from the molecular to the macro-scale. Although new experimental techniques have extended our knowledge of the surface properties of ice and their impact on some single reactions and processes, others occurring on, at or within snow grains remain unquantified. The presence of liquid or liquid-like compartments either due to the formation of brine or disorder at surfaces of snow crystals below the freezing point may strongly modify reaction rates. Therefore, future experiments should include a detailed characterisation of the surface properties of the ice matrices. A further point that remains largely unresolved is the distribution of impurities between the different domains of the condensed phase inside the snowpack, i.e. in the bulk solid, in liquid at the surface or trapped in confined pockets within or between grains, or at the surface. While surface-sensitive laboratory techniques may in the future help to resolve this point for equilibrium conditions, additional uncertainty for the environmental snowpack may be caused by the highly dynamic nature of the snowpack due to the fast metamorphism occurring under certain environmental conditions. Due to these gaps in knowledge the first snow chemistry models have attempted to reproduce certain processes like the long-term incorporation of volatile compounds in snow and firn or the release of reactive species from the snowpack. Although so far none of the models offers a coupled approach of physical and chemical processes or a detailed representation of the different compartments, they have successfully been used to reproduce some field experiments. A fully coupled snow chemistry and physics model remains to be developed.

show abstract

“…This is consistent with previous suggestions that HCl loading at the grain boundaries could lead to local disorder in the ice lattice. 25,27 …”

Section: B Surface Disorder Conditions 1 Smooth and Vapordepositedmentioning

confidence: 99%

Interaction of Hydrogen Chloride with Ice Surfaces: The Effects of Grain Size, Surface Roughness, and Surface Disorder

et al. 2007

View full text Add to dashboard Cite

Characterization of the interaction of hydrogen chloride (HCl) with polar stratospheric cloud (PSC) ice particles is essential to understanding the processes responsible for ozone depletion. The interaction of HCl with ice was studied using a coated-wall flow tube with chemical ionization mass spectrometry (CIMS) between 5 × 10 -8 and 10 -4 Torr HCl and between 186 and 223 K, including conditions recently shown to induce quasiliquid layer (QLL) formation on single crystalline ice samples. Measurements were performed on smooth and rough (vapor-deposited) polycrystalline ice films. A numerical model of the coated-wall flow reactor was used to interpret these results and results of studies on zone-refined ice cylinders with grain sizes on the order of several millimeters (reported elsewhere). We found that HCl adsorption on polycrystalline ice films typically used in laboratory studies under conditions not known to induce surface disordering consists of two modes: one relatively strong mode leading to irreversible adsorption, and one relatively weak binding mode leading to reversible adsorption. We have indirect experimental evidence that these two modes of adsorption correspond to adsorption to sites at crystal faces and those at grain boundaries, but there is not enough information to enable us to conclusively assign each adsorption mode to a type of site. Unlike what was observed in the zone-refined ice study, there was no strong qualitative contrast found between the HCl uptake curves under QLL versus non-QLL conditions for adsorption on smooth and vapor-deposited ices. We also found indirect evidence that HCl hexahydrate formation on ice between 3 × 10 -7 and 2 × 10 -6 Torr HCl and between 186 and 190 K is a process involving hydrate nucleation and propagation on the crystal surface, rather than one originating in grain boundaries, as has been suggested for ice formed at lower temperatures. These results underscore the dependence of the HCl-ice interaction on the characteristics of the ice substrate.

show abstract

Rutherford Backscattering to Study the Near-Surface Region of Volatile Liquids and Solids

Cited by 22 publications

References 18 publications

The rate of water vapor evaporation from ice substrates in the presence of HCl and HBr: implications for the lifetime of atmospheric ice particles

The rate of water vapor evaporation from ice substrates in the presence of HCl and HBr: implications for the lifetime of atmospheric ice particles

A review of air–ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow

Interaction of Hydrogen Chloride with Ice Surfaces: The Effects of Grain Size, Surface Roughness, and Surface Disorder

Contact Info

Product

Resources

About