Roles of Surface/Volume Diffusion in the Growth Kinetics of Elementary Spiral Steps on Ice Basal Faces Grown from Water Vapor

Asakawa, Harutoshi; Sazaki, Gen; Yokoyama, Etsuro; Nagashima, K.; Nakatsubo, Shunichi; Furukawa, Yoshinori

doi:10.1021/cg4014653

Cited by 26 publications

(72 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Blue and red solid lines are guides for the eyes. Black open squares present the solid−vapor equilibrium P H2O that we obtained experimentally from the LCM-DIM observations of the growth and recession of elementary steps and crystal edges (15). Solid and dashed black curves show the solid−vapor equilibrium P H2O and the liquid−vapor equilibrium P H2O , respectively, obtained in previous studies (16,17).…”

Section: Significancementioning

confidence: 68%

“…In other words, α-and β-QLLs could exist only under P H2O conditions higher than these respective plots. Black open squares present the solid−vapor equilibrium P H2O that we determined experimentally from the LCM-DIM observations of the growth and recession of elementary steps and crystal edges (15). Solid and dashed black curves in Fig.…”

Section: Significancementioning

confidence: 97%

“…The black arrowhead (Fig. 1A) depicts an elementary step (0.37 nm in height) growing laterally in the direction of the black arrow (10,11,15). In this study, the differential interference contrast was adjusted as if the ice crystal surface was illuminated by a light beam slanted from the upper left to the lower right direction (Fig.…”

Section: Significancementioning

confidence: 99%

See 2 more Smart Citations

Two types of quasi-liquid layers on ice crystals are formed kinetically

Asakawa

Sazaki

Nagashima

et al. 2016

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

Self Cite

View full text Add to dashboard Cite

Surfaces of ice are covered with thin liquid water layers, called quasi-liquid layers (QLLs), even below their melting point (0°C), which govern a wide variety of phenomena in nature. We recently found that two types of QLL phases appear that exhibit different morphologies (droplets and thin layers) [Sazaki G. et al. (2012) Proc Natl Acad Sci USA 109(4):1052−1055]. However, revealing the thermodynamic stabilities of QLLs remains a longstanding elusive problem. Here we show that both types of QLLs are metastable phases that appear only if the water vapor pressure is higher than a certain critical supersaturation. We directly visualized the QLLs on ice crystal surfaces by advanced optical microscopy, which can detect 0.37-nm-thick elementary steps on ice crystal surfaces. At a certain fixed temperature, as the water vapor pressure decreased, thin-layer QLLs first disappeared, and then droplet QLLs vanished next, although elementary steps of ice crystals were still growing. These results clearly demonstrate that both types of QLLs are kinetically formed, not by the melting of ice surfaces, but by the deposition of supersaturated water vapor on ice surfaces. To our knowledge, this is the first experimental evidence that supersaturation of water vapor plays a crucially important role in the formation of QLLs. molecular-level observation | advanced optical microscopy | metastable phase | supersaturation I ce is one of the most abundant materials on Earth, and its surfaces are covered with thin liquid water layers even below their melting point (0°C) (1-4). Such thin liquid water layers are called "quasi-liquid layers" (QLLs). Because QLLs govern the surface properties of ice just below the melting point, it is well acknowledged that surface melting of ice governs a wide variety of phenomena, such as electrification of thunderclouds (4, 5), regelation (4, 6), frost heave (4, 7), conservation of foods, ice skating (1, 8), preparation of a snowman (1), and growth of ice crystals (2, 4). Therefore, it is essential to understand the surface melting of ice crystals at the molecular level.After Michael Faraday proposed the existence of QLLs in 1842 (1), many studies experimentally confirmed the formation of QLLs by various methods (Table S1). All such studies revealed that the thickness of QLLs significantly increases with increasing temperature. However, such the studies used spectroscopy and scattering methods, which can obtain only temporally and spatially averaged information, or optical microscopy, which does not have sufficient spatial resolution. Hence, the nature of surface melting has not been fully unlocked. To further understand the dynamic behavior of QLLs, we need to perform real-time and real-space observations of ice crystal surfaces at the molecular level.Recently, we and Olympus Engineering Co., Ltd., have developed one such technique, namely, laser confocal microscopy combined with differential interference contrast microscopy (LCM-DIM) (9), which can directly visualize the 0.37-nm-thick elementary steps on...

show abstract

Section: Significancementioning

confidence: 68%

Section: Significancementioning

confidence: 97%

See 1 more Smart Citation

Two types of quasi-liquid layers on ice crystals are formed kinetically

Asakawa

Sazaki

Nagashima

et al. 2016

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

Self Cite

View full text Add to dashboard Cite

show abstract

“…A thermodynamic pathway to form QLLs. For weak supersaturation (undersaturation) near the vapor-ice equilibrium where G ice < G vapor < G qll (G vapor < G ice < G qll ), vapor (ice) directly transforms into ice (vapor) through the layer by layer process following the terrace-step-kink picture (23,(36)(37)(38).…”

Section: Methodsmentioning

confidence: 99%

“…For weak supersaturation (undersaturation) near the vapor-ice equilibrium where the free energy of a QLL is highest among the three phases, vapor (ice) directly transforms into ice (vapor) through the layer-by-layer process driven by 2D nucleation and/or spiral growth (surface hollowing mediated by defects). This is the standard process of crystal growth based on the terrace-step-kink picture (23,(36)(37)(38). However, far from the vapor-ice equilibrium where the free energy of a QLL is intermediate between that of ice and vapor, vapor (ice) transforms into ice (vapor) with accompanying nucleation and growth of metastable QLLs on growing (sublimating) ice surfaces.…”

Section: Thermal Fluctuation Effects: Droplet Nucleation From Thin LImentioning

confidence: 99%

Thermodynamic origin of surface melting on ice crystals

Murata

Asakawa

Nagashima

et al. 2016

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

Self Cite

119

View full text Add to dashboard Cite

Since the pioneering prediction of surface melting by Michael Faraday, it has been widely accepted that thin water layers, called quasi-liquid layers (QLLs), homogeneously and completely wet ice surfaces. Contrary to this conventional wisdom, here we both theoretically and experimentally demonstrate that QLLs have more than two wetting states and that there is a first-order wetting transition between them. Furthermore, we find that QLLs are born not only under supersaturated conditions, as recently reported, but also at undersaturation, but QLLs are absent at equilibrium. This means that QLLs are a metastable transient state formed through vapor growth and sublimation of ice, casting a serious doubt on the conventional understanding presupposing the spontaneous formation of QLLs in ice-vapor equilibrium. We propose a simple but general physical model that consistently explains these aspects of surface melting and QLLs. Our model shows that a unique interfacial potential solely controls both the wetting and thermodynamic behavior of QLLs.surface melting | quasi-liquid layer | advanced optical microscopy | pseudo-partial wetting | wetting transition I n general, surfaces and interfaces yield unique phase transitions absent in the bulk (1-5). Surface melting (or premelting) of ice (3, 4) is one typical and classical example that has been known since the first prediction by Michael Faraday in 1842 (6). He hypothesized that thin water layers, now called quasi-liquid layers (QLLs), wet ice crystal surfaces even at a temperature below the melting point. Since then, this phenomenon has attracted considerable attention not only because of its importance in the fundamental understanding of melting (a solid-toliquid transition) itself but also as a link to a diverse set of natural phenomena in subzero environments: making snowballs, slippage on ice surfaces, frost heave, recrystallization and coarsening of ice grains, morphological change of snow crystals, electrification of thunderclouds, and ozone-depleting reactions (3, 4, 7). Furthermore, it is now recognized that surface melting is not specific to ice but rather is universally seen in a wide range of crystalline surfaces such as metals, semiconductors, ceramics, rare gases, and organic and colloidal systems (8-12). Its underlying physics is therefore also inseparable from material science and technology.Although the origin of surface melting, including the nature of QLLs themselves, is still far from completely understood and a matter of active debate (13-18), it is at least phenomenologically believed that surface melting is driven by the reduction of the surface free energy by the presence of intervening liquid between the solid and gas phases (3,4,13,19). More sophisticated approaches have also been proposed in terms of surface phase transitions (1,3,4,20). In contrast to such theoretical speculations, however, the direct observation and the accurate characterization of QLLs by experiments are still highly challenging because of their thinness, assumed to be less t...

show abstract