Surface reconstructions are herein referred to by Wood s notation (N x M) R(p. N and M refer to the length of the lattice vectors for the surface reconstruction, where the vectors are N and M times the length of the bulk lattice vectors in the plane of the surface. R

surface lattice vectors N and M are rotated by q> degrees with respect to the bulk lattice vectors in the same plane. When R(p is omitted, the angle q> is 0°. Other symmetry indicators can also be included, for example the SrTiOa (100) c(4 x 2) reconstruction has lattice vectors 4 and 2 times the (010) and (001) bulk lattice vectors, in the same direction (0° rotation), while the c indicates that it is a centered unit cell. [Pg.207]

Two sets of notation are commonly used to describe overlayer structures observed in diffraction experiments, the Wood notation [92] and a matrix notation. Although the latter is more flexible, the former is more widely used and we shall restrict ourselves to it in this review. The nomenclature is based on a comparison between the unit mesh of the topmost layer, the overlayer, and that of the second, unreconstructed, substrate layer. If a and b are the unit mesh vectors of the substrate layer and a, and bg the unit mesh vectors of the overlayer, then Wood s notation for an overlayer of adsorbed species A on the hkl plane of a crystal M is [Pg.11]

Fig. A.3 The structure of a few common ordered overlayers and the corresponding Wood s notation. |

In both cases, the adsorbate occupies the T positions with half coverage and the unit cell is then doubled in the h and k directions so the Wood s notation for this [Pg.696]

Adsorbates may form ordered overlayers, which can have their own periodicity. The adsorbate structure is given with respect to that of the substrate metal. For simple arrangements the Wood s notation is used, and some examples are given in Figure A.3. The notation Pt(110)-c(2 x 2)0 means that oxygen atoms form an [Pg.300]

Figure 6.9 illustrates LEED patterns of the clean Rh(lll) surface, and the surface after adsorption of 0.25 monolayer of NH3 [23], The latter orders in the primitive (2 x 2) overlayer structure (see Appendix for the Wood s notation). In [Pg.156]

See also in sourсe #XX -- [ Pg.156 , Pg.158 , Pg.246 , Pg.300 ]

See also in sourсe #XX -- [ Pg.696 , Pg.697 ]

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