The Unreconstruction-Reconstruction Phase Transition of the Pt(110) Surface

沈青嵩(C. S. Shern)

Chinese Journal of Physics

29卷6期（1991 / 12 / 01）

653 - 663

英文

Ar ions with appropriate kinetic energy bombarding on a clean Pt(llO)-(1X2) surface without further annealing produce a (1 X 1) bulklike LEED pattern. Atoms at the topmost layer of this (1X1) surface must be random. The phase transition temperature from unreconstruction (1X1) to reconstruction (1 X2) of the Ar^+ bombarded (1 x 1) surface and the conventional CO-induced (1X1) surface occur at 440 K and 360 K respectively. Both transitions are irreversible. A reversible transition (1 X 2) □ (1 X 1) occurs at 1050 K that belongs to a order-disorder phase transition. From the behaviour of the phase transition, the LEED spot profile and comparable studies with oxygen chemisorbed on two (1 X 1) unreconstructed surfaces and a (1 X 2) reconstructed the surface, we conclude that atoms on the topmost layer of the Pt(llO)-(1 Xl) surface induced by CO are random in position.