The suggested atomic structure of the -phase (00•1) (31 x 31)R 9 reconstruction was analyzed by using grazing-incidence X-ray diffraction techniques. It was found that it consisted of two Al planes whose structure was close to that of metallic Al(111). This layer was rotationally reconstructed, was commensurate with the substrate, and exhibited strong non-linear static distortion waves. The presence of this O-depleted layer explained why the surface properties were markedly different.

G.Renaud, B.Villette, I.Vilfan, A.Bourret: Physical Review Letters, 1994, 73[13], 1825-8