A Fast Frozen Phonon Algorithm Using Mixed Static Potentials

Peters, Jonathan J. P.

doi:10.1016/j.ultramic.2021.113364

Cited by 6 publications

(5 citation statements)

References 28 publications

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“…S5). The matching of these high-resolution HRTEM images to the crystal structure model and simulated HRTEM pattern 70 of a single chain derived from the experimental single crystal structure of Sb2Se3 44 indicates that there is minimal structural modulation in the chain upon encapsulation within a CNT. Specifically, we found that there were only very minimal differences between the direct comparison of the atomic distances of the Sb(1)-Sb(1) crystallographic sites (or Sb(2)-Sb(2); along the chain direction) and Sb(1)-Sb(2) sites (perpendicular to the chain direction) derived from the single crystal structure as compared with the experimental distances measured from HRTEM imaging of Sb2Se3@CNT.…”

Section: Resultsmentioning

confidence: 82%

Single Quasi-1D Chains of Sb2Se3 Encapsulated Within Carbon Nanotubes

Milligan

Cordova

Yao

et al. 2023

Preprint

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The realization of stable monolayers from 2D van der Waals (vdW) solids has fueled the search for exfoliable crystals that possess even lower dimensionalities. To this end, 1D and quasi-1D (q-1D) vdW crystals comprised of weakly-bound chains with sub-nanometer thicknesses have been discovered and demonstrated to exhibit nascent physics in the bulk. Although established micromechanical and liquid phase exfoliation methods have been applied to access single isolated chains from bulk 1D and q-1D vdW crystals, the existence of interchain vdW interactions with non-equivalent strengths has greatly hindered the ability to achieve uniform single isolated chains. Here, we report that encapsulation of the model q-1D vdW crystal, Sb2Se3, within single-walled carbon nanotubes (CNTs) circumvents the relatively stronger vdW interactions between the chains and allows for the isolation of single chains with structural integrity. Comprehensive high-resolution transmission electron microscopy and selected area electron diffraction studies of the Sb2Se3@CNT heterostructure revealed that the structure of the [Sb4Se6]n chain is preserved, enabling us to systematically probe the size-dependent properties of Sb2Se3 from the bulk down to a single chain. We then show that ensembles of the [Sb4Se6]n chains within CNTs display Raman confinement effects and an emergent band-like absorption onset around 600 nm, suggesting a strong blue shift of the near-infrared band gap of Sb2Se3 into the visible range upon encapsulation. First-principles density functional theory calculations further provided a qualitative insight on the structures and interactions that could manifest in the Sb2Se3@CNT heterostructure. From these calculations, spatial visualization of the electron density difference map of the heterostructure indicated the possibility of electron donation from the host CNT to the guest [Sb4Se6]n chain. Altogether, this model system demonstrates that 1D and q-1D vdW crystals with strongly anisotropic vdW interactions can be precisely studied by encapsulation within carbon nanotubes with suitable diameters, thereby opening opportunities in understanding dimension-dependent properties of a plethora of emergent vdW solids at or approaching the sub-nanometer regime.

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Section: Resultsmentioning

confidence: 82%

Single Quasi-1D Chains of Sb2Se3 Encapsulated Within Carbon Nanotubes

Milligan

Cordova

Yao

et al. 2023

Preprint

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“…Close inspection of the high-magnification micrographs of the Sb 2 Se 3 @CNTs also show highly uniform periodicity as evidenced by the consistent lattice fringes that can be indexed closest to [101]-oriented single chains from the parent Sb 2 Se 3 bulk crystal structure ( Figures 3 A,D,E and S6 ). The matching of these high-resolution HRTEM images to the crystal structure model and simulated HRTEM pattern 71 of a single chain derived from the experimental single crystal structure of Sb 2 Se 3 40 indicates that there is minimal structural modulation in the chain upon encapsulation within a CNT. Specifically, we found that there were minimal bond distance differences between the direct comparison of the atomic distances of the Sb(1)–Sb(1) crystallographic sites (or Sb(2)–Sb(2); along the chain direction) and Sb(1)–Sb(2) sites (perpendicular to the chain direction) derived from the single crystal structure as compared to the experimental distances measured from HRTEM imaging of Sb 2 Se 3 @CNT.…”

Section: Resultsmentioning

confidence: 83%

“…Indexing of the SAED and FFT data were performed by comparing the experimental patterns with simulated patterns of the bulk single crystal structure using the SingleCrystal 4 software (CrystalMaker Software Suite). HRTEM images were simulated using the clTEM software 71 from a .xyz file of single chain Sb 2 Se 3 generated in VESTA by extending the unit cell along the b -axis, then manually excluding any atoms that are not covalently bound to the single chain.…”

Section: Methodsmentioning

confidence: 99%

Single Quasi-1D Chains of Sb₂Se₃ Encapsulated within Carbon Nanotubes

Milligan,

Yao,

Cordova

et al. 2024

Chem. Mater.

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The realization of stable monolayers from 2D van der Waals (vdW) solids has fueled the search for exfoliable crystals with even lower dimensionalities. To this end, 1D and quasi-1D (q-1D) vdW crystals comprising weakly bound subnanometer-thick chains have been discovered and demonstrated to exhibit nascent physics in the bulk. Although established micromechanical and liquid-phase exfoliation methods have been applied to access single isolated chains from bulk crystals, interchain vdW interactions with nonequivalent strengths have greatly hindered the ability to achieve uniform single isolated chains. Here, we report that encapsulation of the model q-1D vdW crystal, Sb 2 Se 3 , within single-walled carbon nanotubes (CNTs) circumvents the relatively stronger c-axis vdW interactions between the chains and allows for the isolation of single chains with structural integrity. High-resolution transmission electron microscopy and selected area electron diffraction studies of the Sb 2 Se 3 @CNT heterostructure revealed that the structure of the [Sb 4 Se 6 ] n chain is preserved, enabling us to systematically probe the size-dependent properties of Sb 2 Se 3 from the bulk down to a single chain. We show that ensembles of the [Sb 4 Se 6 ] n chains within CNTs display Raman confinement effects and an emergent band-like absorption onset around 600 nm, suggesting a strong blue shift of the near-infrared band gap of Sb 2 Se 3 into the visible range upon encapsulation. First-principles density functional theory calculations further provided qualitative insight into the structures and interactions that could manifest in the Sb 2 Se 3 @CNT heterostructure. Spatial visualization of the calculated electron density difference map of the heterostructure indicated a minimal degree of electron donation from the host CNT to the guest [Sb 4 Se 6 ] n chain. Altogether, this model system demonstrates that 1D and q-1D vdW crystals with strongly anisotropic vdW interactions can be precisely studied by encapsulation within CNTs with suitable diameters, thereby opening opportunities in understanding dimension-dependent properties of a plethora of emergent vdW solids at or approaching the subnanometer regime.

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“…Diffraction patterns of individual ice domains were indexed using known lattice constants of ice I c and ice I h crystal structures. Diffraction patterns of ice I c+h domains with streaks were compared to ED simulations performed with clTEM 62 to identify the contributions from I c and I h sequences.…”

Section: Methodsmentioning

confidence: 99%

“…The models of I c , I h , and I c+h were generated by MD simulations described in the next section. The TEM simulations and ED simulations were performed by using GPU-accelerated multislice algorithm in clTEM 62 . The parameters including accelerating voltage, defocus, and Cs were used based on parameters for JEM-2100F: 200 kV, 5 nm, and 1 mm, respectively.…”

Section: Methodsmentioning

confidence: 99%

Observing growth and interfacial dynamics of nanocrystalline ice in thin amorphous ice films

Lee,

Kang

et al. 2024

Nat Commun

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Ice crystals at low temperatures exhibit structural polymorphs including hexagonal ice, cubic ice, or a hetero-crystalline mixture of the two phases. Despite the significant implications of structure-dependent roles of ice, mechanisms behind the growths of each polymorph have been difficult to access quantitatively. Using in-situ cryo-electron microscopy and computational ice-dynamics simulations, we directly observe crystalline ice growth in an amorphous ice film of nanoscale thickness, which exhibits three-dimensional ice nucleation and subsequent two-dimensional ice growth. We reveal that nanoscale ice crystals exhibit polymorph-dependent growth kinetics, while hetero-crystalline ice exhibits anisotropic growth, with accelerated growth occurring at the prismatic planes. Fast-growing facets are associated with low-density interfaces that possess higher surface energy, driving tetrahedral ordering of interfacial H2O molecules and accelerating ice growth. These findings, based on nanoscale observations, improve our understanding on early stages of ice formation and mechanistic roles of the ice interface.

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A Fast Frozen Phonon Algorithm Using Mixed Static Potentials

Cited by 6 publications

References 28 publications

Single Quasi-1D Chains of Sb2Se3 Encapsulated Within Carbon Nanotubes

Single Quasi-1D Chains of Sb2Se3 Encapsulated Within Carbon Nanotubes

Single Quasi-1D Chains of Sb₂Se₃ Encapsulated within Carbon Nanotubes

Observing growth and interfacial dynamics of nanocrystalline ice in thin amorphous ice films

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A Fast Frozen Phonon Algorithm Using Mixed Static Potentials

Cited by 6 publications

References 28 publications

Single Quasi-1D Chains of Sb2Se3 Encapsulated Within Carbon Nanotubes

Single Quasi-1D Chains of Sb2Se3 Encapsulated Within Carbon Nanotubes

Single Quasi-1D Chains of Sb2Se3 Encapsulated within Carbon Nanotubes

Observing growth and interfacial dynamics of nanocrystalline ice in thin amorphous ice films

Contact Info

Product

Resources

About

Single Quasi-1D Chains of Sb₂Se₃ Encapsulated within Carbon Nanotubes