The temporal evolution of the surface topography and X-ray spectrum of
gold thin films is obtained. We found by scanning tunneling microscop
y that the surface roughness decreases exponentially with time. As the
X-ray incidence angle decreases the peak positions shift and the peak
half-widths increase. These results indicate that microcrystals in th
e surface are under strain and are smaller than in the bulk. The X-ray
peak positions shift with elapsed time towards the gold standards. Th
e conclusion of the study is that rearrangement of the gold film surfa
ce is induced by surface strains that appear during film growth. Thus,
the surface smoothing is due to relaxation of the stress in the mater
ial rather than to the thermal motion of atoms.