Abstract:
This review is a collection of twelve original papers concerning
growth and interface modification in the Co/Cu system. Most of this
research has been carried out in the Laboratory of Surface and Thin Film
Physics at the Institute of Nuclear Physics. The Laboratory was created by
the author of this review in 1996 in strong collaboration with the Institute
of Nuclear Physics Wilhelms-Universität in Münster, Germany and the
Institute of Applied Physics Ukrainian Academy of Science in Sumy,
Ukraine. The big international team worked under the leadership of Dr
Marta Marszałek, initially developing a multicomponent ultrahigh vacuum
setup for thin film preparation and analysis, and next accompanying her
in studies of the structural, magnetic and magnetotransport properties of
Co/Cu multilayers.
Systems that exhibit giant magnetoresistance effect have been
receiving intensive attentions over recent years since they are possible
candidates for applications in ultrahigh-density data storage and
magnetoelectronic devices. The focus of this research is the growth of
magnetic Co/Cu multilayers modified by using metallic surface modifiers
called surfactants. The different approaches have been used. Surfactant
metals were introduced once into growth process as a buffer layer or they
were deposited sequentially at each interface of Co/Cu multilayers. The
growth was performed by molecular beam epitaxy technique which allows
to tailor carefully deposition conditions. The results showed that two
approaches gave different results. Surfactant buffer layers resulted in
loss of layered character of multilayers being a kind of an intermediate
cluster-like phase combined with a layered area. Small amount of
surfactants introduced at each interface lead to well-ordered structures
with small roughness and smoother interfaces than in the case of pure
Co/Cu multilayers. Despite of the differences, in both cases the
improvement of magnetoresistance value was observed.
The atomic scale study of Co growth on Cu(111) surface in the
presence of In surfactant demonstrated that surfactant facilitates layerby-
layer growth of cobalt on Cu(111). The surfactant effect of indium is
connected to a reduction in the cobalt surface diffusion rate (with
increased energy barrier) and therefore lowered ratio of Ehrlich-
Schwoebel barrier to surface diffusion barrier.
