Bragg peaks, LEED

Fig. 44. Dynamic scaling in the growth of Bragg peaks for LEED scattering from oxygen monolayers at 0 = 1/2 and T — 297 K for adsorption in the p(2xl) structure on W(110). Different symbols denote different times t in seconds) after the adsorption has taken place. The halfwidth (used for normalization exactly as in fig. 43) is denoted by FWHM ( full width at half maximum ). From Wu et al. (1989).

This situation is continuously improving, for example, by taking the diffuse parts of the LEED intensity into account. As in the case of X-ray structure analysis, the intensity between the Bragg peaks carries additional information [73, 87]. 

From LEED measurements of H monolayers adsorbed on Fe(110) Imbihl et al. proposed a phase diagram as shown in Fig. IS. In addition to lattice gas and lattice fluid phases, two commensurate ordered phases were identifled, denoted as (2 x 1) and (3 x 1) in the figure (cf. Fig. 16). The shaded regions are interpreted as incommensurate phases or as phases composed of antiphase domains their signature is that the LEED spot does not occur at the Bragg position but rather the peak is splitted and satellites appear (Fig. 17). 

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