We have successfully controlled the surface structures of GaAs(001) by changing incident As-molecular species. Under As4 fluxes, the c(4 x 4) reconstruction with Ga-As dimers [c(4 x 4)alpha structure] is obtained, but the formation of three As-As dimer structures [c(4 x 4)beta structure] is kinetically limited. On the other hand, the structure change from the (2 x 4), through c(4 x 4)alpha, to c(4 x 4)beta phases is observed under As2 fluxes. We found that the c(4 x 4)alpha structure is energetically metastable and provides a kinetic pathway for the structure change between the (2 x 4) and c(4 x 4)beta phases under As2 fluxes.

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http://dx.doi.org/10.1103/PhysRevLett.92.236105DOI Listing

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