RT info:eu-repo/semantics/article T1 Phonon Modes at the2H−NbSe2Surface Observed by Grazing Incidence Inelastic X-Ray Scattering A1 Murphy, B. M. A1 Requardt, H. A1 Stettner, J. A1 Krisch, M. A1 Müller, M. A1 Press, W. A1 Serrano Gutiérrez, Jorge AB We have determined the dispersion of acoustic and optical surface phonon modes at the 2H−NbSe2 by inelastic x-ray scattering under grazing incidence conditions. Already, at room temperature, an anomaly is observed close to the charge density wave Q-vector position located at about one-third along the Γ−M direction of the Brillouin zone. Our results indicate that the anomaly for the surface mode occurs at a lower energy than that measured in bulk sensitive geometry in the same experiment, showing evidence of a modified behavior in the uppermost layers. We demonstrate that inelastic x-ray scattering in grazing incidence conditions provides a unique tool to selectively study either surface or bulk lattice dynamics in a single experiment. PB American Physical Society SN 0031-9007 YR 2005 FD 2005 LK https://uvadoc.uva.es/handle/10324/65329 UL https://uvadoc.uva.es/handle/10324/65329 LA eng NO Phys. Rev. Lett. 95, 256104 (2005) DS UVaDOC RD 22-nov-2024