Takahasi Masamitu, Mizuki Jun'ichiro
Synchrotron Radiation Research Center, Japan Atomic Energy Research Institute, Mikazuki-cho, Hyogo 679-5148, Japan.
Phys Rev Lett. 2006 Feb 10;96(5):055506. doi: 10.1103/PhysRevLett.96.055506. Epub 2006 Feb 8.
In situ structure analysis of GaAs(001)-c(4 x 4) has been carried out by synchrotron surface x-ray diffraction, which is sensitive to the three-dimensional structure and the atomic species. On the basis of 98 independent in-plane diffractions and 11 fractional-order rod profiles, the atomic coordinates and thermal vibration parameters were determined. X-ray diffraction results show the buckling of surface dimers and a strain field extending up to the sixth layer from the surface. An anomalous diffraction technique has been employed to specify the atomic species of the surface dimers. It has provided direct evidence of the formation of Ga-As heterodimers.
