Surface Phonon of MgO Layer on TiC(100) Surface

Abstract

The surface phonon of a hetero-epitaxial MgO layer on a TiC(100) surface has been investigated using high-resolution electron energy loss spectroscopy (HREELS). The Fuchs-Kliewer, Rayleigh and Wallis modes of MgO were detected. The vibration energy of the F-K wave in the MgO layer was higher than that of a MgO single crystal due to the two-dimensional character of the MgO layer. The Rayleigh mode having almost the same dispersion relationship with bulk MgO was measured at the non-zero wave vector. Among the microscopic surface phonons, the Wallis mode ( S2) has been detected, vibrational energy of which was the same as that of bulk.