The dispersion of the phonons of the LaB6(111) surface has been measured and reproduced on the basis of lattice dynamical calculations. The surface force constants were found to be different from the bulk force constants. In particular, the force constant of an interoctahedral boron-boron bond at the surface increases by 50% from the corresponding bulk force constant. From the relationship between the force constant and bond length in various hexaborides, we have estimated the contraction of the interoctahedral bond length to be 0.007 nm. The deformation of the boron network on the (111) surface, the behavior of which is similar to that on the (100) surface, is explained by the inherent nature of the boron network.
|出版ステータス||Published - 1998 10 30|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Condensed Matter Physics
- Surfaces and Interfaces