W. Platow et al., Structure of ultrathin Ni/Cu(001) films as a function of film thickness, temperature, and magnetic order, PHYS REV B, 59(19), 1999, pp. 12641-12646
We report on a detailed structural study of ultrathin Ni films on Cu(100) a
pplying quantitative low-energy electron diffraction. The analysis of films
with different thickness shows that the film growth is pseudomorphic throu
ghout the coverage regime investigated, 1-11 monolayers. The vertical spaci
ngs of the Ni layers, which are unreconstructed, are largely independent of
both film thickness and depth. They are by about 3.2% contracted compared
to the bulk spacings of Ni (5% compared to the bulk spacings of Cu), so tha
t all films correspond to homogeneous tetragonal phases. Due to the tetrago
nal distortion, the volume of Ni atoms in the films is practically the same
as in bulk Ni. The layer spacing at the Ni-Cu interface is slightly contra
cted compared to the value resulting from a hard sphere model, and the same
holds for the top Cu layer distance. In particular, within the accuracy li
mits (1-2% or less) we detect no structural differences for the change from
in-plane to vertical magnetization with varying coverage or temperature or
for the change from ferro- to paramagnetism at the Curie temperature. [S01
63-1829(99)03719-4].