Low-energy electron diffraction from quasicrystal surfaces

The discovery of ordered but aperiodic quasicrystal structures has required the development of new diffraction methods to determine their structures. The purpose of this review is to highlight the challenges posed by the aperiodicity of quasicrystals to the study of their surface structures by low-energy electron diffraction (LEED). This paper describes how the LEED technique has been thus far adapted to study several quasiperiodic surface structures, and summarizes the results of those studies. It also presents new spot-profile-analysis LEED results from the fivefold surface of Al-Pd-Mn. An x-ray diffraction experiment and a He-atom diffraction experiment, both on Al-Pd-Mn, are also described for comparison. (topical review)