Ab initio determination of the (100) surfaces phonon dispersions of the SiC

in this work, we presented our preliminary ab initio results for the vibrational modes and the phonon frequencies of the sic (100) surfaces. our results are in good agreement with the available experimental data whenever this comparison is possible. for the accepted models of the c-terminated surfaces in the c(2×2) reconstruction, while in the bridge-dimer model there is an acetylene-like vibrational a1 mode at 2031 cm-1, which is infrared active, in the staggered-dimer model, there is a füchs-kliewer (fk) mode at 1328 cm-1, which is experimentally detected. for si-terminated surfaces in the p(2×1) reconstruction, instead, no fk was obtained, in contradiction with the hreels experimental results for the si-terminated surfaces, but they are in consonance with the fact that this surface should be described by a (3×2) or more complex models.