  In the present investigation, the novel two-step electrochemical process of
room temperature synthesis of Hg-1212 superconducting films has been developed
and reported first time. Electrochemical parameters were optimized by studying
cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry
(CA) for the deposition of Hg-Ba-Ca-Cu alloy at room temperature. Current time
transient showed progressive growth with hemispheriodal granules, which were
then revealed by scanning electron microscopy (SEM). Stoichiometric
electrocrystallization to get Hg1Ba2Ca1Cu2O6+x (Hg-1212) was completed by
electrochemically intercalating oxygen species into Hg-Ba-Ca-Cu alloy at room
temperature. The oxygen content in the samples was varied by varying the
electrochemical oxidation period and the changes in the crystal structure,
microstructure, and superconducting transition temperature (Tc) and critical
current density (Jc) were recorded. The films oxidized for 28 min showed Tc =
104.7 K with Jc = 1.437 x 103 A/cm2. The dependence of superconducting
parameters on oxygen content is correlated with structure property relations
and reported in this paper.
