Miller index, high notation

We should mention here a special notation used for describing high-Miller-index surfaces. Such surfaces can often be more usefully described as stepped surfaces involving relatively close-packed terraces of low-Miller-index orientation separated by steps whose faces have also a low-Miller-index orientation. For example, the fcc(755) surface can be more easily visualized with the notation fcc(S)-[6(l 11)X (100)], where (S) means stepped , since this indicates that the surface is composed of terraces of (111) orientation and 6 atoms wide, separated by steps of (100) orientation and 1 atom high. A list of such correspondences of notation for stepped fee surfaces is included in Sect. V. 

Notation of High-Miller-Index, Stepped Surfaces... 

A notation for these surfaces, the compact-step notation, devised by Lang and Somoijai [3], gives the surface structure in the general form w h,k,l,) X (h kj,), where hjc,l,) and h kj,) are the Miller indices of the terrace plane and the step plane, respectively, while w is the number of atoms that are counted in the width of the terrace, including the step-edge atom and the in-step atom. Thus, the fcc(755) surface is denoted by 7(111) x 1(100), or also by 7(111) x (100) for simplicity. A stepped surface with steps that are themselves high-Miller-index faces is termed a kinked surface. For example, the fcc(10, 8, 7) = 7(111) X (310) surface is a kinked surface. The step notation is, of course, equally applicable to surfaces of bcc, hep, and other ciystals, in addition to surfaces of fee crystals. Stepped surfaces of several orientations are listed in Table 2.2 (p. 88). Here the crystal faces are denoted both by their Miller indices and by their stepped-surface notation. 

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