Growth, crystal structure and stability of Ag-Ni/Cu films
I. K. Bdikin
1,2
, G. K. Strukova
1
, G.V. Strukov
1
, V.V. Kedrov
1
, D.V. Matveev
1
,
S. A. Zver’kov
1
, A. L. Kholkin
2
1
Institute of Solid State Physics, Chernogolovka, Moscow distr. 142432, Russia
2
Department of Ceramics and Glass Engineering and Center for Research in Ceramic and
Composite Materials (CICECO), University of Aveiro, 3810-193, Aveiro, Portugal
ABSTRACT
Ag
x
Ni
1-x
(x=0.0-1.0) films were grown on Cu substrates by electrodeposition
method. The films were found to be a nanocrystalline mixture of pure silver and
nickel. The grain sizes were determined by X-ray diffraction and electron microscopy
techniques. The minimal value was 3.3 nm for the alloy with 70 wt% Ni
concentration. The stability of the grown films upon heating in air and in vacuum was
examined. An increase in the grain size was found to begin at 150 °C.
INTRODUCTION
Magnetic and nonmagnetic metal two-component nanostructures attract significant
interest not only in view of fundamental physics involved, but also due to the possibility
of using them for magnetic recording and magnetoresistive devices [1]. The Ag-Ni
system is among the least studied. To the best of our knowledge, only one paper reported
preparation of a nanocrystalline Ag-Ni alloy by mechanical alloying [2]. Most
publications were concerned with amorphous and nanocrystalline Ni-Co [3], Ni-W [4],
Ni-Si [5], Ni-Fe [6-8], and Ag-Co [9] alloys. The phase diagram of the Ag-Ni system has
the simplest form: there are no intermediate phases, the elements are mutually insoluble
fully immiscible and do not intermix even in the liquid state [10]. This may be due, in
particular, to a large atomic misfit (~15%) of the crystal lattices of the elements with the
same lattice type (fcc).
The electrodeposition method of depositing thin metal films has many advantages.
It can be carried out at ambient temperature and pressure, and therefore requires much
less complex apparatus than the vacuum-based techniques such as molecular beam
epitaxy or sputtering. The electrodeposition with non-aqueous solution has additional
advantages in comparison with aqueous solution, including environmental safety and
capability of depositing wider range of metals and alloys.
The goal of this paper was to study the structure of Ag-Ni films of various
compositions grown by co-electrodeposition in non-aqueous solution containing Ag and
Ni ions. This co-electrodeposition method has been developed earlier by the authors [11]
for different alloys of precious metals.
EXPERIMENTAL DETAILS
Ag-Ni films with typical thickness 100-500 nm were grown on copper substrates by
electrodeposition. In this technique, we used a single electrolyte containing Ag and Ni
ions. Deposition was carried out at room temperature in a three-electrode standard
Mater. Res. Soc. Symp. Proc. Vol. 854E © 2005 Materials Research Society U8.17.1