Surface Crystallography: Surface crystallography is especially difficult because the diffraction is dominated by the bulk solid with only very weak contributions from the reconstructed surface. (A difference in mean intensity of the order of 10-8.) Most of the data are only two-dimensional. Traditional direct methods have great difficulty here. Three papers have been published, however, in which the ME formalism has been applied including the highly complex Si(111) 7x7 surface and TiO2 where the hitherto accepted structure has been proved to be incorrect.
Si(111)7x7 surface (on right)and an maximum entropy reconstruction at 1.5A resolution on the left |
References for Surface Crystallography