The optical anisotropy of Pt(100) studied by reflection anisotropy spectroscopy

The optical anisotropy of the Pt(100) hex-R0.7° reconstructed phase is studied with reflection anisotropy spectroscopy. The transition from the hex-R0.7° to the Pt(1 × 1) structure is also studied. The spectrum of Pt(100) hex-R0.7° is found to be dominated by surface polariton-like absorption due to the wavy nature of the first layer superstructure, but an additional absorption is also observed in the reconstructed layer. After exposure to CO the surface transforms to a Pt(1 × 1) surface covered with Pt islands. The growth of the (1 × 1) phase is highly anisotropic, i.e. the growth being much faster along the [011] direction than along [011]. The islands are elongated in the fast growth direction and an optical anisotropy from the island covered surface is observed which is comparable to that of the Pt(100) hex-R0.7° surface.