Abstract
Raman spectroscopic analysis of polycrystalline and single crystal of stoichiometric Si and Ge type II clathrates was presented. Density functional, plane-wave pseudopotential calculations were used to calculate the vibrational modes of clathrates. The 457.9 and 514.5 nm excitation of an Ar-ion laser, 647.1 nm excitation of a Kr-ion laser, and 700 nm excitation of a Ti-sapphire laser were used in Raman scattering measurements. Lowest frequency Raman-active optic 'rattle' mode, which corresponded to the vibrations of Cs atoms inside the hexakaidecahedra, was identified for Si and Ge clathrate compounds.
Original language | English |
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Pages (from-to) | 7225-7230 |
Number of pages | 6 |
Journal | Journal of Applied Physics |
Volume | 92 |
Issue number | 12 |
DOIs | |
State | Published - Dec 15 2002 |