Energies of the phases of ice at low temperature and pressure relative to ice Ih

Handa, Y. P.; Klug, D. D.; Whalley, E.

doi:10.1139/v88-156

Cited by 78 publications

(100 citation statements)

References 11 publications

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“…This requires some consideration of nucleus shape, which is taken to be approximately spherical, consistent with calculations of the interfacial free energy at the basal, prism, and (1120) faces. 15 Experimental 23 One source of variation in these figures is the range of methods by which "cubic ice" is obtained from other ice phases, 17 consistent with these samples actually representing stacking disordered ice with varying degrees of cubic content. It is therefore likely that most measurements underestimate G hc.…”

Section: Stacking Modelmentioning

confidence: 85%

Communication: Thermodynamics of stacking disorder in ice nuclei

Quigley

2014

The Journal of Chemical Physics

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A simple Ising-like model for the stacking thermodynamics of ice 1 is constructed for nuclei in supercooled water, and combined with classical nucleation theory. For relative stabilities of cubic and hexagonal ice I within the range of experimental estimates, this predicts critical nuclei are stacking disordered at strong sub-cooling, consistent with recent experiments. At higher temperatures nucleation of pure hexagonal ice is recovered. Lattice-switching Monte-Carlo is applied to accurately compute the relative stability of cubic and hexagonal ice for the popular mW model of water. Results demonstrate that this model fails to adequately capture the relative energetics of the two polytypes, leading to stacking disorder at all temperatures. © 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

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Section: Stacking Modelmentioning

confidence: 85%

Communication: Thermodynamics of stacking disorder in ice nuclei

Quigley

2014

The Journal of Chemical Physics

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“…In 1942, König (7) discovered that at low temperatures water occasionally crystallizes into a different modification, cubic ice Ic. Subsequently, cubic ice has been produced in the laboratory, e.g., by condensing water vapor onto cooled substrates (7-11), by heating amorphous solid water (7-9), by supercooling liquid water droplets (12-14) or clusters (15), or by freezing high-pressure phases of ice and reheating them at atmospheric pressure (16)(17)(18)(19). Cubic ice has been proposed to also occur naturally, e.g., in the earth's atmosphere (13,(20)(21)(22)(23)(24) and in comets (25,26).…”

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confidence: 99%

“…When ice Ic is heated above 170 K it transforms irreversibly into ice Ih. The release of a measurable amount of heat (on the order of 35 J/mol) (17)(18)(19) establishes hexagonal ice as the equilibrium structure above 170 K. Below 170 K no phase transformation has been observed, allowing for the possibility that at these low temperatures cubic ice is energetically preferred (1,29). Johari (27) argues that contributions from grain-boundary, interphase, and strain energies suppress the formation of hexagonal ice in bulk cubic ice.…”

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confidence: 99%

Formation of hexagonal and cubic ice during low-temperature growth

Thürmer

Nie

2013

Proc. Natl. Acad. Sci. U.S.A.

106

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From our daily life we are familiar with hexagonal ice, but at very low temperature ice can exist in a different structure--that of cubic ice. Seeking to unravel the enigmatic relationship between these two low-pressure phases, we examined their formation on a Pt (111) substrate at low temperatures with scanning tunneling microscopy and atomic force microscopy. After completion of the onemolecule-thick wetting layer, 3D clusters of hexagonal ice grow via layer nucleation. The coalescence of these clusters creates a rich scenario of domain-boundary and screw-dislocation formation. We discovered that during subsequent growth, domain boundaries are replaced by growth spirals around screw dislocations, and that the nature of these spirals determines whether ice adopts the cubic or the hexagonal structure. Initially, most of these spirals are single, i.e., they host a screw dislocation with a Burgers vector connecting neighboring molecular planes, and produce cubic ice. Films thicker than ∼20 nm, however, are dominated by double spirals. Their abundance is surprising because they require a Burgers vector spanning two molecular-layer spacings, distorting the crystal lattice to a larger extent. We propose that these double spirals grow at the expense of the initially more common single spirals for an energetic reason: they produce hexagonal ice.ice growth mechanisms | molecular surface steps | molecular-layer nucleation | scanning probe microscopy | spiral growth O wing to its ubiquity in nature, ice and its structural properties have inspired widespread interest (1, 2). Not long after the introduction of X-ray diffraction in 1912, the structure of the most common modification of ice, hexagonal ice Ih, had already been investigated extensively (1-6). In 1942, König (7) discovered that at low temperatures water occasionally crystallizes into a different modification, cubic ice Ic. Subsequently, cubic ice has been produced in the laboratory, e.g., by condensing water vapor onto cooled substrates (7-11), by heating amorphous solid water (7-9), by supercooling liquid water droplets (12-14) or clusters (15), or by freezing high-pressure phases of ice and reheating them at atmospheric pressure (16)(17)(18)(19). Cubic ice has been proposed to also occur naturally, e.g., in the earth's atmosphere (13,(20)(21)(22)(23)(24) and in comets (25,26). However, even after thousands of articles dedicated to ice formation have appeared, important questions regarding fundamental growth mechanisms of ice remain. Some of these questions concerning the competition between the two lowpressure crystalline phases ice Ih and ice Ic are addressed in this paper.Ice Ih and ice Ic have been observed to coexist at temperatures up to 240 K (10-12, 18, 27, 28). When ice Ic is heated above 170 K it transforms irreversibly into ice Ih. The release of a measurable amount of heat (on the order of 35 J/mol) (17-19) establishes hexagonal ice as the equilibrium structure above 170 K. Below 170 K no phase transformation has been observed, allowing for the poss...

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“…[34] So far it has not been possible to prepare Ic without glide-type stacking faults and disorder. [35] Ih and Ic are not distinguishable by means of Raman or infrared spectroscopy.…”

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confidence: 99%

High Density Amorphous Ice from Cubic Ice

et al. 2006

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Supercooled water does not behave like a simple liquid, but instead shows a number of anomalous properties.[1] These include the diffusion coefficient [2] or the kinematic viscosity [3] which show anomalous pressure dependencies on compression up to % 200 MPa, whereas beyond % 200 MPa the expected behaviour is observed. To explain these anomalies the second critical point hypothesis has been put forward, [4] in which a first-order-like phase transition between a low-(LDL) and high-density liquid (HDL) is thought to occur. LDL and HDL become indistinguishable above the second critical point, which is postulated to be in the "no man's land" around 180-220 K and 100-340 MPa, [5][6][7][8] where only crystalline ice has been observed experimentally. This model is supported by the observation that there are (at least) two different phases of amorphous water called low-(LDA) and high-density amorphous ice (HDA), [9,10] which have been found to show a first-order like transformation in compression/decompression experiments. [11,12] On heating, LDA and HDA experience a glass-transition to the highly viscous, supercooled liquids denoted low-(LDL) and high-density liquid (HDL), respectively. [13][14][15][16][17] The role of HDA in this model has become unclear since the discovery of a further distinct structural state called very-high density amorphous ice (VHDA).[18] It has lately been argued that only VHDA and LDA are homogeneous disordered structures, whereas HDA does not constitute a particular state of the HDA network.[19] This issue is still under debate, since the transition from HDA to VHDA on isothermal compression at 125 K has been found recently to be similar to the transition from LDA to HDA.[20] The detailed structures of recovered HDA and VHDA have been determined at ambient pressure and 77 K by means of neutron diffraction with isotope substitution. [21,22] These two studies contain the first experimental determination of the three site-site distribution functions (HÀH, OÀO, OÀH). For both HDA and VHDA there is no evidence in the diffraction pattern to show that it is microcrystalline rather than a genuinely amorphous structure.Herein, we show that HDA produced by pressure-induced amorphization of cubic ice (Ic) at 77 K is not the same material as "traditional" HDA produced by pressure-induced amorphization of hexagonal ice (Ih) at 77 K. [23,24] The density of both amorphous states recovered at ambient pressure is very similar; however, the X-ray structure factor as well as the phase transition characteristics in differential scanning calorimetry scans, differ in the onset temperature, enthalpy and sharpness of the exotherms.Hexagonal ice was prepared by either pipetting 0.300 mL of deionized water directly into the piston-cylinder apparatus lined with an indium container kept at 77 K, or by heating HDA close to ambient pressure to % 260 K and recovering to 77 K and 1 bar, or by Johari's procedure of decompressing HDA to 0.06 GPa and heating to 235 K.[25] Cubic ice was prepared by hyperquenching small liquid ...

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Energies of the phases of ice at low temperature and pressure relative to ice Ih

Cited by 78 publications

References 11 publications

Communication: Thermodynamics of stacking disorder in ice nuclei

Communication: Thermodynamics of stacking disorder in ice nuclei

Formation of hexagonal and cubic ice during low-temperature growth

High Density Amorphous Ice from Cubic Ice

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