is Amorphous#

Catchy Phrase


Amorphous water ice, shapeless and still,
A formless beauty that seems to spill,
Over surfaces, with no defined shape,
A sight thatā€™s unique and hard to escape.

Itā€™s formed when water freezes fast,
And loses its structure in the cast,
Of cold and rapid freezing pace,
A sight that seems to hold its place.

Itā€™s found on comets, asteroids, and more,
A form of water thatā€™s hard to ignore,
A substance thatā€™s elusive and rare,
A beauty thatā€™s formed without a care.

Itā€™s a sight to behold, with its misty form,
A beauty that seems to weather the storm,
Of time and space, and endless nights,
A thing of beauty, pure and bright.

So let us marvel at amorphous ice,
A substance formed in a flash, precise,
A wonder thatā€™s hard to replicate,
A beauty thatā€™s formed without a mistake.

ā€“ Vince (& ChatGPT)

Iceberg

Intro catchy phrase

Amorphous

Note

Change image with Pierre picture


Plan

Water Molecule

Condensed phase

Water Models

Hexagonal Ice



Plan

Key Litterature:



Links

  • 1
  • 2

Amorphous Ices#

Litterature#

Study Title Year ā€œInfrared spectra of amorphous solid waterā€ by G.A. Baratta and J.A. Westley 1989 ā€œInfrared spectra of amorphous solid water: Implications for interstellar and cometary iceā€ by L.D. Deshmukh et al. 2004 ā€œH2O ice in the interstellar medium: a comparison between observed and simulated infrared spectraā€ by C.A. Boogert et al. 2015 ā€œIce grain morphology and infrared spectra in protoplanetary disksā€ by M. Min et al. 2016 ā€œThe Low-Temperature Infrared Spectrum of Amorphous Solid Water: A Spectroscopic and Theoretical Studyā€ by J. P. Lewis et al. 2000 ā€œMid-infrared spectroscopy of interstellar ice analogsā€ by J.M. Brown et al. 2007 ā€œA laboratory study of the mid-infrared spectra of amorphous solid water and water-rich icesā€ by A.G.G.M. Tielens et al. 2008 ā€œSpectroscopic properties of amorphous solid water: a reviewā€ by P. Ehrenfreund et al. 2015

Review#

  • Review []

Bulk Organisation#

Definition#
Experiments#
  • Variation of the deposition angle

Controlling the Morphology of Amorphous Solid Water

  • Deposition temperature variations
  • Annealing processes

Porosity#

[]

Definition#
  • Controlling the
Experiments#
  • Different types

Insert here table of different groups:

  • NASA Ames: Mastrapa, Sandford
    • Is data available, yes

Infrared Spectroscopy#


Key Papers:

  • Mastrapa (2008, 2009)
  • Jenny

What did we leran#
  • ASW is porous
  • 3 Āµm band is changing when the T is increased
  • Water ice IR Band assignement taken from []

Warning

table was ther but got suppressed, to check

to cite:

Note

  • TO, LO, what does this mean ?

Insert own crystaline and amorphous spectra with different asssignments vertical bar

Link with Optical Constants

  • Real and imaginary part (how do they relate to what we observe in space)

Differential Scanning Calorimetry#

tg at 136K (ramp 30K.min-1) ā€“> Increase in heat capacity (lower than other amorphous solid: similar to SiO2 - GeO2) ā€“> Imply limited number of entropically different configurational states in the fluid state following tg

Dielectric relaxation behaviour expected to be determined by two processes both involving a thermaly activated dipolar reorientation:

  • translational-rotational diffusion of water molecules if the whole H-Bonded network relaxed within limitation of entropically different configurations
  • rotational diffusion of water molecules within a fixed H-Bonded structure as breaches of the Bernal-Fowler rules. ā€“> 2 kinds of Bjerrum defects
    • Scattering

ASW at 140K - true glass or very viscous liquid ? What is the difference

Crystalisation#

At molecular scales (few molecules up to 100 ?) - Matrix isolation techniques

Water_moleucule

Desorption#

[]

Porosity#

[]

  • []

Is it Amorphous ?#

Amorphous-ice/Amorphous/Docs/Ice-process-PPD1.PNG

Fig. 8 Source#