Electrodeposition as a new route to synthesize superconducting FeSe

Abstract

We have successfully synthesized FeSe films by the electrochemical deposition in the electrolyte containing FeCl_{2}\cdot4H_{2}O, SeO_{2} and Na_{2}SO_{4}. The composition ratio of Fe and Se was controlled by the synthesis voltage and pH value. The FeSe film with the composition ratio of Fe : Se = 1 : 1 is fabricated at a voltage of -0.9 V and pH 2.1 in our electrochemical deposition. This sample has a highly crystalline tetragonal FeSe structure and exhibits a superconducting transition at 8.1 K, comparable to FeSe synthesized by other methods.