scholarly journals Identifying Raman modes of Sb2Se3 and their symmetries using angle-resolved polarised Raman spectra

2020 ◽  
Vol 8 (17) ◽  
pp. 8337-8344 ◽  
Author(s):  
Nicole Fleck ◽  
Theodore D. C. Hobson ◽  
Christopher N. Savory ◽  
John Buckeridge ◽  
Tim D. Veal ◽  
...  

Vibrational symmetry assignments using Raman spectroscopy and density functional theory on oriented crystals also enabling orientation optimisation of thin films.

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 643 ◽  
Author(s):  
Javier Gonzalez-Platas ◽  
Placida Rodriguez-Hernandez ◽  
Alfonso Muñoz ◽  
U. R. Rodríguez-Mendoza ◽  
Gwilherm Nénert ◽  
...  

Synthetic chalcomenite-type cupric selenite CuSeO3∙2H2O has been studied at room temperature under compression up to pressures of 8 GPa by means of single-crystal X-ray diffraction, Raman spectroscopy, and density-functional theory. According to X-ray diffraction, the orthorhombic phase undergoes an isostructural phase transition at 4.0(5) GPa with the thermodynamic character being first-order. This conclusion is supported by Raman spectroscopy studies that have detected the phase transition at 4.5(2) GPa and by the first-principles computing simulations. The structure solution at different pressures has provided information on the change with pressure of unit–cell parameters as well as on the bond and polyhedral compressibility. A Birch–Murnaghan equation of state has been fitted to the unit–cell volume data. We found that chalcomenite is highly compressible with a bulk modulus of 42–49 GPa. The possible mechanism driving changes in the crystal structure is discussed, being the behavior of CuSeO3∙2H2O mainly dominated by the large compressibility of the coordination polyhedron of Cu. On top of that, an assignation of Raman modes is proposed based upon density-functional theory and the pressure dependence of Raman modes discussed. Finally, the pressure dependence of phonon frequencies experimentally determined is also reported.


2015 ◽  
Vol 33 (2) ◽  
pp. 286-291
Author(s):  
Abdul Shakoor ◽  
Fayyaz Hussain ◽  
Najmul Hassan ◽  
Abdul Majid ◽  
Muhammad Tariq Bhatti ◽  
...  

AbstractRaman scattering investigations based on density functional theory (DFT) calculations were performed to explore the vibrational modes of a cadmium hexathiohypodiphosphate CdPS3 single crystal. The calculations were performed to obtain the Raman spectra for the cadmium hexathiohypodiphosphate atoms to study the size dependence. Several vibrational modes indicating stretching and bending features related to Cd, S and P atoms were observed. Modifications of the frequency and intensity of different Raman modes with an increase in the number of atoms in CdPS3 were discussed in detail. Hydrogen atoms were added in order to make the closed shell configuration and saturate the CdPS3 as per the requisite for calculating the Raman spectra. This produced some additional modes of vibration related to hydrogen atoms. Band gap and formation energy were also calculated. The results generated are found to be in close agreement with the experimental values.


Author(s):  
Javier Gonzalez-Platas ◽  
Placida Rodriguez-Hernandez ◽  
Alfonso Muñoz ◽  
Ulises Rodriguez-Mendoza ◽  
Gwilherm Nenert ◽  
...  

Synthetic chalcomenite-type cupric selenite CuSeO3∙2H2O has been studied at room temperature under compression up to pressures of 8 GPa by means of single-crystal X-ray diffraction, Raman spectroscopy, and density-functional theory. According to X-ray diffraction, the orthorhombic phase undergoes an isostructural phase transition at 4.0(5) GPa with the thermodynamic character being first-order. This conclusion is supported by Raman spectroscopy studies which have detected the phase transition at 4.5(2) GPa and by the first-principles computing simulations. The structure solution at different pressures has provided information on the change with pressure of unit-cell parameters as well as on the bond and polyhedral compressibility. A Birch-Murnaghan equation of state has been fitted to the unit-cell volume data. We found that chalcomenite is highly compressible with a bulk modulus of 42 – 49 GPa. The possible mechanism driving changes in the crystal structure is discussed, being the behavior of CuSeO3∙2H2O mainly dominated by the large compressibility of the coordination polyhedron of Cu. On top of that, an assignation of Raman modes is proposed based upon density-functional theory and the pressure dependence of Raman modes discussed. Finally, the pressure dependence of phonon frequencies is also reported.


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