Oscillatory Adatom-Adatom Interactions of 1D and 2D Surface Diffusion Systems

Tsu-Yi Fu；Te-Yi Wu；Tien T. Tsong

Chinese Journal of Physics

43卷1S期（2005 / 02 / 01）

124 - 131

英文

Direct observations with the field ion microscope make it possible to determine the probability P(R) of finding two atoms on a surface at a separation R at equilibrium at temperature T. The free energy of interaction F(R) can be obtained from the relation: P(R) ∝ exp[-F(R)/kT]. For the 1D diffusion system, the interactions of two Pd atoms on the W(211) plane are studied for following cases: two Pd atoms in the same, and in the nearest channels. Oscillatory behaviors of these interactions along the channel direction are observed and analyzed with data fitting. For the 2D diffusion system, the interactions of two W atoms on the Ir(111) plane are studied. The oscillatory behaviors are not only observed in the interaction energy versus adsorbate separation curve, but also along the [2, -1, -1] and [-1, 0, 1] axes. The interaction energy of the different systems and cases is discussed.