Mode Assignment of Sulfur α-S<sub>8</sub> by Polarized Raman and FTIR Studies at Low Temperatures

Becucci, Maurizio; Bini, Roberto; Castellucci, E.; Eckert, Bodo; Jodl, H. J.

doi:10.1021/jp963029r

Cited by 37 publications

(25 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, we compare the lowest calculated, mostly external modes (T = 0 K, without ZPE) with experimental results from vibrational spectroscopy below 20 K ( Table 2). 70 Unfortunately, we cannot compare all frequencies because some phonon modes accessible by IR and Raman are still unassigned.…”

Section: A Ground-state Properties and Lattice Dynamicsmentioning

confidence: 99%

Lattice thermal expansion and anisotropic displacements in 𝜶-sulfur from diffraction experiments and first-principles theory

George

Deringer

Wang

et al. 2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

Thermal properties of solid-state materials are a fundamental topic of study with important practical implications. For example, anisotropic displacement parameters (ADPs) are routinely used in physics, chemistry, and crystallography to quantify the thermal motion of atoms in crystals. ADPs are commonly derived from diffraction experiments, but recent developments have also enabled their first-principles prediction using periodic density-functional theory (DFT). Here, we combine experiments and dispersion-corrected DFT to quantify lattice thermal expansion and ADPs in crystalline α-sulfur (S), a prototypical elemental solid that is controlled by the interplay of covalent and van der Waals interactions. We begin by reporting on single-crystal and powder X-ray diffraction measurements that provide new and improved reference data from 10 K up to room temperature. We then use several popular dispersion-corrected DFT methods to predict vibrational and thermal properties of α-sulfur, including the anisotropic lattice thermal expansion. Hereafter, ADPs are derived in the commonly used harmonic approximation (in the computed zero-Kelvin structure) and also in the quasi-harmonic approximation (QHA) which takes the predicted lattice thermal expansion into account. At the PPBE+D3(BJ) level, the QHA leads to excellent agreement with experiments. Finally, more general implications of this study for theory and experiment are discussed.

show abstract

Section: A Ground-state Properties and Lattice Dynamicsmentioning

confidence: 99%

Lattice thermal expansion and anisotropic displacements in 𝜶-sulfur from diffraction experiments and first-principles theory

George

Deringer

Wang

et al. 2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…The Se chains or rings have a Raman peak at around 255 cm −1 . Regarding S‐based structural units, GeS 4/2 tetrahedral vibration modes are at 344 cm −1 and 395 cm −1 , the pyramidal SbS 3/2 structural units have the peaks at 280 cm −1 and 308 cm −1 , and the S chains or rings have a vibration around 475 cm −1 …”

Section: Resultsmentioning

confidence: 99%

“…15 Regarding S-based structural units, GeS 4/2 tetrahedral vibration modes are at 344 cm À1 and 395 cm À1 , [16][17][18] the pyramidal SbS 3/2 structural units have the peaks at 280 cm À1 and 308 cm À1 , 18,19 and the S chains or rings have a vibration around 475 cm À1 . 18,20,21 In order to quantify the evolution of the structural units, Raman spectra of these glasses were decomposed into multiple Gaussians that correspond to the different structural units as shown in Figure 4 as well. The relative ratio of the integrated area of each decomposed peak to that of the whole Raman spectra was shown in Figure 5.…”

Section: Resultsmentioning

confidence: 99%

Structure and physical properties of Ge₁₅Sb₂₀Se_65‐_xS_x glasses

Wang

Liu

et al. 2017

J Am Ceram Soc

View full text Add to dashboard Cite

We explored the structure and physical properties of Ge15Sb20Se65‐xSx (with x = 0, 16.25, 32.5, 48.75, and 65) glasses in order to screen the best compositions for the applications in photonics, since the laser damage thresholds in Se‐based glasses are too low although their optical nonlinearities are high. We found that, linear and nonlinear refractive index of the glasses decreased, but glass transition temperature Tg, optical bandgap Eg and the laser damage threshold increased with increasing S content. We further employed Raman scattering and high‐resolution X‐ray photoelectron spectra to probe the structure of the glasses. Through the analysis of the evolution of the different structural units in the glasses, it was concluded that, the heteropolar bonds (Ge–Se/S, Sb–Se/S) were dominated in these glasses. With the increase in chalcogen Se/S ratio, the number of the Se‐related chemical bonds (Ge–Se, Sb–Se and Se–Se) increased and that of S‐related chemical bond (Ge–S, Sb–S and S–S) decreased gradually, and Ge was prior to bond with S rather than Se. The elemental substitution thus had negligible effect on the glass structure. The change of the physical properties was mainly due to the difference of the strength of the chemical bonds between S–Ge(Sb) and Se–Ge(Sb).

show abstract

“…The intramolecular potential included a harmonic well term for the SSS angle and a torsional potential of the double well type for the sulfur chain, different from hydrocarbon chains that show a triple well torsional potential. These intramolecular coordinates fully describe all the low frequency intramolecular modes that mix with lattice modes [8,9] and can, therefore, be relevant for the lattice stability or in the onset of structural phase transitions.…”

Section: Introductionmentioning

confidence: 99%

Toward an anisotropic atom–atom model for the crystalline phases of the molecular S8 compound

Pastorino

Gamba

2001

The Journal of Chemical Physics

View full text Add to dashboard Cite

We analize two anisotropic atom-atom models used to describe the crystalline α, β and γ phases of S 8 crystals, the most stable compound of elemental sulfur in solid phases, at ambient pressure and T < ∼ 400 K. The calculations are performed via a series of classical molecular dynamics (MD) simulations, with flexible molecular models and using a constant pressure-constant temperature algorithm for the numerical simulations. All intramolecular modes that mix with lattice modes, and are therefore relevant on the onset of structural phase transitions, are taken into account.Comparisons with experimental data and previous results obtained with an isotropic atom-atom molecular model are also performed.

show abstract

Mode Assignment of Sulfur α-S₈ by Polarized Raman and FTIR Studies at Low Temperatures

Cited by 37 publications

References 20 publications

Lattice thermal expansion and anisotropic displacements in 𝜶-sulfur from diffraction experiments and first-principles theory

Lattice thermal expansion and anisotropic displacements in 𝜶-sulfur from diffraction experiments and first-principles theory

Structure and physical properties of Ge₁₅Sb₂₀Se_65‐_xS_x glasses

Toward an anisotropic atom–atom model for the crystalline phases of the molecular S8 compound

Contact Info

Product

Resources

About

Mode Assignment of Sulfur α-S8 by Polarized Raman and FTIR Studies at Low Temperatures

Cited by 37 publications

References 20 publications

Lattice thermal expansion and anisotropic displacements in 𝜶-sulfur from diffraction experiments and first-principles theory

Lattice thermal expansion and anisotropic displacements in 𝜶-sulfur from diffraction experiments and first-principles theory

Structure and physical properties of Ge15Sb20Se65‐xSx glasses

Toward an anisotropic atom–atom model for the crystalline phases of the molecular S8 compound

Contact Info

Product

Resources

About

Mode Assignment of Sulfur α-S₈ by Polarized Raman and FTIR Studies at Low Temperatures

Structure and physical properties of Ge₁₅Sb₂₀Se_65‐_xS_x glasses