Thermal Desorption of H2O-Ice: From Nanoscale Films to the Bulk
arXiv:2204.07053 · doi:10.1093/mnras/stac2803
Abstract
Desorption of H2O films ranging from 53 nanometres to 101 micrometre thicknesses have been investigated using a quartz-crystal microbalance (QCM) and temperature-programmed desorption. Three desorption stages are observed belonging to amorphous solid water (ASW), stacking disordered ice I (ice Isd), and hexagonal ice I (ice Ih). The desorption of ASW is only visible for the >10 micrometre films and is separated from the ice I desorption by 10-15 K and has an associated desorption energy of 64 kJ mol-1. The desorption energy of the 53 nanometre film was found to be near 50 kJ mol-1 as also noted in the literature, but with increasing film thickness the desorption energy of ice I rises until reaching a plateau around 65-70 kJ mol-1. The reason for the increased desorption energy is suggested to be due to molecules unable to desorb due to the thick covering layer of H2O and possibly re-adsorption. Before complete desorption of ice I which occurs around 220 K for the 100 micrometre film, a two-stage ice I desorption is observed with the QCM for the 10 and 20 micrometre films near 200 K. This event corresponds to the desorption of ice Isd as corroborated by X-ray diffraction patterns collected upon heating from 92-260 K at ambient pressure. Cubic ice is not observed as is commonly stated in the literature as resulting from the crystallisation of ASW. Therefore, ice Isd is the correct terminology for the initial crystallisation product of ASW.
References in corpus (20)
- A molecular perspective of water at metal interfaces
- The c2d Spitzer Spectroscopic Survey of Ices Around Low-Mass Young Stellar Objects: I. H2O and the 5-8 um Bands
- The stickiness of micrometer-sized water-ice particles
- Evaporation of ices near massive stars: models based on laboratory TPD data
- Thermal Desorption of Water-Ice in the Interstellar Medium
- Surface Compositions Across Pluto and Charon
- Atom addition reactions in interstellar ice analogues
- Ice and Dust in the Quiescent Medium of Isolated Dense Cores
- Cubic ice Ic free from stacking defects synthesized from ice XVII
- Ice Ic without stacking disorder by evacuating hydrogen from hydrogen hydrate
- Extent of stacking disorder in diamond
- Microgravity experiments on the collisional behavior of Saturnian ring particles
- Breaking the Ice: Planetesimal Formation at the Snowline
- Temperature programed desorption of water ice from the surface of amorphous carbon and silicate grains as related to planet-forming disks
- Micrometer-Sized Water Ice Particles for Planetary Science Experiments: Influence of Surface Structure on Collisional Properties
- Collisions of small ice particles under microgravity conditions
- Implications of Surface Roughness in Models of Water Desorption on the Moon
- A new structural relaxation pathway of low-density amorphous ice
- Ohmic heating of asteroids around magnetic stars
- Ice coverage of dust grains in cold astrophysical environments