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RESEARCH PRODUCT
Vibrational Properties of InSe under Pressure: Experiment and Theory
Ulrich S. SchwarzV. MuñozClemens UlrichK. SyassenAndrés CantareroM. A. MroginskiAlejandro R. Goñisubject
DiffractionChemistryScatteringPhononAnalytical chemistryPressure experimentCondensed Matter PhysicsMolecular physicsResonance (particle physics)Electronic Optical and Magnetic MaterialsCondensed Matter::Materials Sciencesymbols.namesakeMolecular vibrationsymbolsRaman spectroscopyRaman scatteringdescription
The pressure dependence of the phonon modes in the layered semiconductor γ-InSe has been investigated experimentally and theoretically for pressures up to 11 GPa. The mode Gruneisen parameters of all Raman-active zone-center phonons have been determined by Raman scattering under pressure. In addition, features corresponding to second and third-order scattering processes are apparent in the Raman spectra under resonance conditions, from which information about zone-edge modes can be obtained. For the assignment of the observed Raman features to vibrational modes we have calculated the phonon dispersion curves using a rigid-ion model including couplings to first-nearest neighbors and long-range Coulomb interaction. At about 7 GPa the sample turns from transparent to opaque and a new Raman mode appears in the spectra at around 165 cm−1. This is evidence of a pressure-induced structural instability of γ-InSe, which is optically detected but not by X-ray diffraction.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1996-11-01 | physica status solidi (b) |