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Structures of 2D and 3D Me alloys

First attempts using combined electrochemical and in situ STM measurements were carried out in systems Au(lll)/Pb, H, C104 [3.193-3.195, 3.300], Ag(lll)/Tl, H 0104, and Ag(lll)/Pb , H , C104 [3.175, 3.177-3.179]. The results show clearly that the surface morphology is drastically changed due to 2D Me-S surface alloy formation. [Pg.134]

However, a small surface area fraction, which corresponds to upper terrace regions at monatomic steps, remains uncovered. The filling of these surface regions, i.e., completion of the first 2D Me overlayer, occurs at lower A corresponding to adsorption peak A3 in Figs. 3.53 and 3.54 as represented in Fig. 3.60, [Pg.135]

2D Tlads overlayers at low, medium, and high F show internally compressed and rotated hep superstructures with moire pattern as shown in Figs. 3.33 and 3.34 (cf. Section 3.4). The formation of a 2D Me-S surface alloy starts at monatomic steps after extended polarization at relatively high Tor low AE, i.e., between the adsorption peaks A2 and A3 of Figs. 3.53 and 3.54. [Pg.136]

Coexisting domains of expanded and condensed surface structures are observed as shown in Fig. 3.61. The expanded surface structure should be formally described by an Ag(lll)-(-s X VS) R 30° structure, but can be attributed to 2D Me-S surface alloy formation starting at monatomic steps. The condensed surface structure corresponds to the compressed and rotated hep structure of the 2D Meads overlayer. A similar model for 2D Me-S surface alloy formation in the system Au(lll)/Pb, H, CIO4 was suggested by Green [3.195]. [Pg.137]

In agreement with experimental results, a limited Meads overlayer formation at monatomic steps in the initial stage is proposed in both models [3.109, 3.175, 3.177-3.179, 3.195]. The physical reason for this interesting phenomenon is still unknown. Possibly, different local energetics of Meads Meadj-Meads internal [Pg.137]




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2D structures

3D structures

Alloys, structure

Of 2D structures

Of 3D structures

Structural alloys

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