Ultrathin Ag films grown epitaxially on Pt(111) were studied by photoe
lectron forward scattering using synchrotron radiation. The complete a
ngular distributions of the Ag 3d electrons at similar to 500 eV kinet
ic energy were recorded in a cone with 88 degrees opening angle using
a two-dimensional display-type analyzer. The images reveal that the se
cond Ag layer grows at room temperature predominantly in a hcp stackin
g sequence with respect to the pseudomorphic first Ag layer, After ann
ealing to 750 K most of the second layer Ag atoms assume fee sites, Fu
rther Ag layers continue to grow in a fee stacking sequence relative t
o the first two Ag layers. Annealing does not change the stacking of t
hicker films. Thick fee Ag films can be grown in a twin orientation wi
th respect to the Pt(111) substrate at room temperature or in the subs
trate orientation if the second Ag layer is annealed.