Discovery & History#

of Amorphous Ice


Introduction

While most people are familiar with the crystalline structure of ice, there is another form of ice that is less well-known: Amorphous Solid Water (ASW). In this section, we will explore in depth what amorphous solid water is, how it has been discovered, how it is formed and its significance in various fields of study.

Plan


  • Summary

Notes

Discovery#

Amorphous solid water, is a form of ice that lacks a crystalline structure. It is also referred to as non-crystalline, glassy, or vitreous ice. Unlike crystalline ice, which has a well-defined periodic arrangement of molecules, ASW is disordered and lacks long-range order (similar to glass)

The first experimental description of amorphous water ice has been achieved in 1935 by [] that deposited water vapor on a copper rod maintained at -155 ℃ It has since been an intense subject of research involving multiple production method and characterisation techniques.

» Amorphous Solids #

Amorphous ice does not naturally form under Earth conditions (Pressure and Temperature)

That is why you may not be familliar with it, however there is a whole diversity of amorphous materials that you may encounter in your everyday life:

» » Examples #

Glass

Rubber

Asphalt

Plastics

Wax

Resins

Reminder video:

» Amorphous vs Crystaline ice #

Note

insert 2 MD structure to show the differences

We have seen crystaline ice in previous chapter (link)

Long range order …

Amorphous ice is …

../../_images/ASW_vs_cryst.png

Fig. 9 Source- Arxiv - to extract and put in bib#

» Supercooled liquid and Glasses #

[Ediger et al., 1996]

» Water Polyamorphism #

Note

Definition

Note

  • Jenniskens
    • []
    • []

To read and extract why those papers are controversial.

How many Amorphous Ices is there ?#

  • [] 5 main categories of Amorphous ice
  • []: High-density ASW annealing, neutron & X-ray diffraction, 5 distinct ASW forms – all metastable at each anneal T, structure evolves systematically between 4 – 8 K.

ASW

HGW

LDA

HDA

vHDA

../../_images/Amorphous_high_low_cat.png
Check slideshow type to include different way of classifying them

Characterised by their mass densities, respectively 0.92, 1.15 and 1.25 g.cm-2

Other forms#

  • IDA: Intermediate Density Amorphous
    • Can’t be considered a polyamorph because can’t be equilibrated
  • MDA: Medium Density Amorphous

High Density vs Low density #

Note

How do they differ

  • OO distances …

Radial distribution function …

Medium Density ? #

» Production Method #

A key parameter for the production of those various forms is the different production method. We will split them in 2 categories:

High Pressure#

Low pressure#

  • ASW
    • Vapor deposited …
  • HGW

Note

In this book, we will speak about ASW

Make link toward Thesis.B HGW section

Amorphous Solid Water#

Note

  • different experimental conditions different forms of ice …

ASW vs Ih vs Clathrate#

  • Review: []

Investigation techniques#

Experimental#

Note

  • Create html tables with all ASW experiments.
    • 1 table for all experiments
    • 1 entry per scientific group

Unclassified yet: []

Warning

table was ther but got suppressed, to check

Dielectric relaxation#

Explain technique

Warning

table was ther but got suppressed, to check

Calorimetric studies#

TPD (Temperature Program Desorption) / DSC (Differential Scanning Calorimetry)

Warning

table was ther but got suppressed, to check

Infrared Spectroscopy#

Absorption / Reflection

Water alone or in mixture

flag alt > Onion layers

Warning

table was ther but got suppressed, to check

Optical constants - necessary to produce “artificial” spectra necessary to fit observation. Experimental spectra can also be directly feated to observation cf Alexis work.

Scattering Experiments#

XRay/ Neutron

Best technique to obtain information on crystal structure. Costly and lots of other constraints.

Other#

Jenny, Bar-Num … Electron microscopy …

Download Giulia’s paper

Simulations#

Molecular Dynamics#

  • [Essmann and Geiger, 1995]: Molecular dynamics simulation, vapour deposited ASW, compared to neutron scattering data from high & low density ASW (pressure induced transformation of crystalline ice), result: vapour deposited ASW between the other two, but closer to high density ASW, agreement with vapour deposited ASW neutron scattering & electron diffraction studies, ASW surface layer deeply fissured (-> high porosity of vapour deposited ice).

» Investigation techniques #

Scattering #

X-RAY#

[]

Neutron#

  • Incoherent inelastic neutron scattering []: Neutron scattering of HDA (from pressure0induced amorphisation), LDA (from annealing HDA, hyperquenched liquid water, Ih, & Ic, H-bond interaction in LDA differ from hyperquenched water & are stronger than in HDA.

Spectroscopy #

More#

  • positron and positronium annihilation []

Production method#


[] - Matrix sublimation method for the formation of high density amorphous ice


  • Why ?

Questions

  • difference between vitreous material and amorphous solid ?
  • Glassy vs vitreous ?

[Narten et al., 1976] showed that different deposition temperatures using the same vapor deposition setup and methodology would lead to two different forms of amorphous ice, where those differences are inferred from diffraction data (both Neutron and X-Ray):

Ice deposited at 77K is low density

  • Diffraction pattern consistent with a structure that has oxygen-oxygen nearest-neighbor tetrahedral symmetry on average, and a nearest neighbor 0-0 separation of 2.76 &#8491 with small dispersion; -> What is meant by this ?

  • Density estimated 0.94 g.cm-3

Ice deposited at 10K is high density

  • Diffraction pattern similar to, yet distinctively different from, that of the high temperature deposit. The 0-0 nearest neighbor distance is the same. 2.76 &#8491 but the dispersion in this separation is larger in the low temperature form.

  • Diffraction pattern shows an extra peak at 3.3 &#8491. corresponding to about 1.4 molecules. the existence of which is responsible for the estimated higher density, namely 1.1 g.cm-3

Question

How is the density determined from Diffraction data

When subject to increasing pressure, amorphous ice soften (what is meant by this ?) and then suddenly collapse to a denser but still amorphous phase. This result is verified by computer simulations where density and structure of the high density amorphous form depends on the potential function chosen to represent the water.

  • to verify (ref 5 - 7) simulation 8-9

Despite the non-crytalline nature of the molecular arrangements in LDA, both the thermodynamic state and the vibrational characteristics are those of a highly ordered substance. The heat carrying phonons of low temperature amorphous water behave like those in a crystal.

  • What does this mean, where does it come from ? Similar (but less dramatic) behaviour have been observed in other tetrahedrally coordinated solid (SiO2, GeO2, ZNCl2 etc).

ASW#

Vapor deposition methods were employed to prepare ASW for the following studies:

  • Calorimetry
  • Spectroscopy
  • vapor pressure and free energy
  • Crystalisation 33,35,34,36
  • Dielectric relaxation
  • Neutron and X-ray diffraction structure studies
  • diffusion studies
  • electron microscope
  • vibrational dynamics studies (by neutron scattering)
  • Thermal conductivity studies

The sharp crystallization exotherm commencing in the range of 150–160 K during reheating is the one universal feature of all previous studies of ASW or vitreous water.

Other preparation techniques#

  • cold microtoming method (68)
  • decompression amorphization (73)
  • electron bombardment vitrification (67, 76, 76a) - could be compatible with accoustic levitation
  • radiation damage–induced vitrification (77)
  • phase-separation vitrification (12)
  • plunge freeze (67)

Note

strong upswing in heat capacity seen in bulk laboratory supercooling water (81)

Heat capacity increase is also a main varying parameter obeserved during glass transition (Tg)

Narten et al. (39)

  • random structure of ASW.
  • second form of ASW - additional peak at 3.3 ̊Angstrom (interstitial water molecule) - Higher density (observed at 10K)
  • First indication of the existence of polyamorphism

do they coexist in metastable equilibrium Mishima 5-7

Structure#

Amorphous vs Crystaline Ice#

How does amorphous ices differs from its crystaline conterpart ? Well it depends on the formation route of the amorphous ice.

Crystaline

  • Polymorph: 18 ?
  • Ice rules

Amorphous

  • Polymorph: 5
  • Structure dependant on deposition conditions

Note

  • Show 2 samples deposited at different T conditions
  • Same T but different thickness

Amorphous ice - supercooled liquid water

Morphology#

  • []

Influence of the Substrate#

  • [Smith et al., 1996]
    • desorption kinetics are substrate dependent and suggest strongly that the film morphology is governed by the hydrophilicity of the substrate.
    • crystallization kinetics are independent of substrate but depend strongly on both temperature and film thickness and are consistent with a spatially random nucleation and isotropic growth model.
  • []
    • dramatic acceleration of the crystallization rate is observed for amorphous films on crystalline ice substrates
    • crystallization-induced cracking of the films

To check

  • Katrina …

ASW Properties#

Note

Debye frequency spectrum

Vibrational dynamics#

  • 2, 28, 30, 31, 61, 82, 91, 105, 107
  • Rice and coworkers (29 - 30b) review 2

Note

  • Dangling bonds in crystaline solids (106)

Scientic field of interest#

Material Sciences#

Note

proximity with liquid water

Atmospheric Science#

ASW plays an important role in atmospheric processes, such as cloud formation and ice nucleation. Clouds are formed when water vapor in the atmosphere condenses onto tiny particles, such as dust or pollen, forming droplets. In certain conditions, such as at high altitudes, these droplets can freeze and form ice crystals. The presence of ASW can affect the freezing point of water, which can have significant implications for cloud formation and atmospheric processes.