  The superconducting FeSe films were successfully fabricated using the
electrochemical synthesis. The composition ratio of Fe and Se can be controlled
by the electric potential and pH value. We found that the FeSe films deposited
at the electric potential -1.75 V and pH 2.3 show the superconducting
transition at 3.5 K. The establishment of this electrochemical synthesis
technique will provide many advantages for application.
