Crystal growth and properties of R2Ba2CuPtO8 (R = Ho, Er, Y), R2Ba3Cu2PtO10 and Ba4CuPt2O9

Saito, Yoko; Shishido, Toetsu; Toyota, Naoki; Ukei, K.; Sasaki, T.; Fukuda, Tsuguo

doi:10.1016/0022-0248(91)90211-m

Cited by 18 publications

(13 citation statements)

References 7 publications

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“…We also found that the planar fronts become destabilized for a particular combination of ΔT and λ, giving rise to parabolic needle-like and parabolic dendrite crystals. As expected for parabolic crystals, the crystal growth proceeds steadily with time (i.e., in proportion to t ) . In many applications, a planar front could be more desired, and in this respect, thorough experimental and computational investigations of the impact of ΔT and surface tension on the stability of gas hydrate planar fronts could be relevant.…”

Section: Discussionmentioning

confidence: 87%

“…While some crystals grow with a parabolic needle geometry, others develop side branches forming what are known as parabolic dendrites . As Figure e shows, the difference in growth rate between the planar regions and the growing crystals is because the CO 2 molar fraction gradient is more prominent in the water region in front of the crystal tips.…”

Section: Simulation Resultsmentioning

confidence: 97%

“…The position of interface follows a power law (length ∝ t 1/2 ), indicating a planar crystal diffusion-controlled growth in which the planar crystals do not grow steadily. Thus, its growing velocity decreases proportionately to t –1/2 …”

Section: Simulation Resultsmentioning

confidence: 99%

“…This interface is the region of volume where the transition between the solid hydrate state and liquid state occurs and can be considered as an integration (solidification) layer that consists of a number of water cages under formation. The modeling approach’s physical processes are (1) the thermodynamics of phase transformation between the two phases at the moving hydrate-water interface, (2) the interfacial attachment (or integration) kinetics of CO 2 molecules at that interface, and (3) the diffusion of CO 2 molecules inside the stagnant liquid water region . These processes are the centerpieces of this work, as we aim to simulate hydrate crystal growth and assess how the pertinent mechanisms give rise to morphological changes.…”

Section: Modeling Approachmentioning

confidence: 99%

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Stochastic Cellular Automata Modeling of CO₂ Hydrate Growth and Morphology

Pineda

Phan

Koh

et al. 2023

Crystal Growth & Design

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Carbon dioxide (CO 2 ) hydrates are important in a diverse range of applications and technologies in the environmental and energy fields. The development of such technologies relies on fundamental understanding, which necessitates not only experimental but also computational studies of the growth behavior of CO 2 hydrates and the factors affecting their crystal morphology. As experimental observations show that the morphology of CO 2 hydrate particles differs depending on growth conditions, a detailed understanding of the relation between the hydrate structure and growth conditions would be helpful. To this end, this work adopts a modeling approach based on hybrid probabilistic cellular automata to investigate variations in CO 2 hydrate crystal morphology during hydrate growth from stagnant liquid water presaturated with CO 2 . The model, which uses free energy density profiles as inputs, correlates the variations in growth morphology to the system subcooling ΔT, i.e., the temperature deficiency from the triple CO 2 −hydrate−water equilibrium temperature under a given pressure, and properties of the growing hydrate-water interface, such as surface tension and curvature. The model predicts that when ΔT is large, parabolic needle-like or dendrite crystals emerge from planar fronts that deform and lose stability. In agreement with chemical diffusion-limited growth, the position of such planar fronts versus time follows a power law. In contrast, the tips of the emerging parabolic crystals steadily grow in proportion to time. The modeling framework is computationally fast and produces complex growth morphology phenomena under diffusion-controlled growth from simple, easy-to-implement rules, opening the way for employing it in multiscale modeling of gas hydrates.

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Section: Discussionmentioning

confidence: 87%

Section: Simulation Resultsmentioning

confidence: 97%

Section: Simulation Resultsmentioning

confidence: 99%

Section: Modeling Approachmentioning

confidence: 99%

See 2 more Smart Citations

Stochastic Cellular Automata Modeling of CO₂ Hydrate Growth and Morphology

Pineda

Phan

Koh

et al. 2023

Crystal Growth & Design

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show abstract

“…The structure consists of chains containing two face-sharing octahedra separated by one face-sharing trigonal prism. Other m = 1, n = 3 members of this family are known and include Sr 4 CuIr 2 O 9 [20], Sr 4 ZnIr 2 O 9 [20], Sr 0.5 Ca 0.5 Co 3 O 9 , Sr 4 Ni 3 O 9 , [21], Sr 4 Mn 2 NiO 9 [8], Sr 4 Mn 2 CuO 9 [22], Ba 4 CuIr 2 O 9 [20], Ba 4 ZnIr 2 O 9 [20], Ba 4 CuPt 2 O 9 [23] and Ba 4 Pt 3 O 9 [24] as well as some cation deficient compositions, Sr 4 Ru 2 O 9 [25] and Sr 4 Ni 2.5 O 9 [26]. During the process of trying to grow rhodium-rich strontium iron rhodium oxide single crystals, we also synthesized SrFe 0.71 Rh 0.29 O 3 , a cubic perovskite containing iron and rhodium in the +4 oxidation state.…”

Section: Introductionmentioning

confidence: 99%