Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 8, pp. 1163−1166.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © G.I. Medvedev, A.A. Rybin, N.A. Makrushin, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 8, pp. 1220−1224.
AND INDUSTRIAL INORGANIC CHEMISTRY
A Study of the Electrodeposition Kinetics of a Tin–Indium Alloy
from a Sulfate Electrolyte with Organic Additives
G. I. Medvedev, A. A. Rybin, and N. A. Makrushin
Novomoskovsk Institute, Mendeleev Russian University of Chemical Engineering,
Novomoskovsk, Tula oblast, Russia
Received May 12, 2012
Abstract—The electrodeposition kinetics of a tin–indium alloy from a sulfate electrolyte in the simultaneous
presence of synthanol DS-10, formalin, and 1,4-butynediol was studied by a Faraday impedance method..
In , we studied the electrodeposition of the tin–in-
dium alloy from a sulfate electrolyte in the simultaneous
presence of synthanol DS-10, formalin, and 1,4-butyne-
diol. It was shown that high-quality alloy coatings are
formed in the simultaneous presence of these organic
substances at i
= 1–7 A dm
. It was of interest to exam-
ine the electrodeposition kinetics of the Sn–In alloy in
the presence of organic substances.
The electrodeposition kinetics of the Sn–In alloy
was studied by the Faraday impedance method 
in an electrolyte of composition (g L
O 20, H
100. The organic
substances were introduced into the electrolyte in the
following amounts: synthanol (DS-10) 2 g L
aldehyde (37% solution) 6 mL L
, and 1,4-butynediol
(35% solution 10 mL L
The differential capacity was measured in the course
of electrolysis with an R-5022 ac bridge in the frequen-
cy range from 20 Hz to 50 kHz on an electrode made of
a platinum wire (S = 0.126 cm
) coated with the Sn–In
alloy, placed at the center of a platinum-plated platinum
Electrochemical measurements were made with a
P-5878 potentiostat. A 10-μm-thick layer of a Sn–In al-
loy containing 10% In and 90% Sn was deposited onto
the surface of the working electrode. Prior to measure-
ments, the electrode surface was refreshed at each po-
tential. The discrepancy between the results of measure-
ments in separate series did not exceed 5%.
The potentials are given relative the standard hydro-
gen electrode (s.h.e.). The differential capacitys in the
electrolyte with organic additives are given with consid-
eration for the roughness factor f. The procedure used to
determine f was described in .
Quantum-chemical calculations of the interaction of
tin and indium ions with water molecules, SO
and the organic substances were made using the PM3
semi-empirical method [4, 5].
Results obtained in measurements of the differen-
tial capacity C at various electrode potentials demon-
strated that C varies with increasing frequency and has
a constant value at 40–50 kHz. Based on this fact, we
accepted that the differential capacity measured at these
frequencies is the capacity of the electric double layer
We performed our measurements with a series equiv-
alent circuit. The values of C
, obtained using
the ac bridge, were recalculated to C
equivalence of the circuit was determined by the proce-
dure described in . The components of the electrode
, were analyzed as functions of
and electrode potential.
Measurements of the cathodic current density and
EDL capacity as a function of the electrode potential
(E = –0.3…–0.7 V) demonstrated that the organic
additives inhibit the electrodeposition of the alloy