Surface diffusion of gold on quasihexagonal-reconstructed Au(100)

The scanning tunneling microscope has been used to measure the saturation island density N(x) of gold on the hexreconstructed Au(100) surface over a range of temperatures starting at 76 K. Assuming that the critical island size equals one, partial derivative lnN(x)/partial derivative(1/T) = chi E(d)/k, where chi is the scaling exponent, E(d) gives the activation energy for surface diffusion, and k is the Boltzmann constant. The scaling exponent chi has been obtained as 0.26 +/- 0.03 from measurements of the island density as a function of the deposition rate, indicating that diffusion is indeed one-dimensional (anisotropic) and the critical island size is unity. We therefore derive an activation energy of 0.32 +/- 0.02eV and a frequency prefactor of 2(x4(+/1)) x 10(13) s(-1) for diffusion of gold on hex-reconstructed Au(100).