金属元素の表面偏析による結合状態の変化と仕事関数 Relation between Change of Binding Energy and That of Work Function
The characteristic features of segregation phenomenon of a substrate element on a deposited film on the substrate bring the self-controlling property of surface composition. This property is advantageous to fabricate material to obtain constant work function. The change of work function and binding energy was measured when Cu segregated on Ti surface and Ti on Cu surface. The work function decreased approximately 0.3 eV by Cu segregation on Ti, while it increased approximately 0.2 eV by Ti segregation on Cu. The binding energy of Cu in both specimens was higher that that of pure Cu, which suggested that an electron of Cu was partially transferred to Ti in both cases. The charge transfer resulted in an electric dipole on the surface with the opposite direction for two cases : a positive charge towards vacuum in Cu segregation and a negative charge in Ti segregation. Those dipoles explain the above work function change in both cases.
真空 42(3), 290-292, 1999-03
The Vacuum Society of Japan