Superconductivity in FeTe{1-x}S_x induced by electrochemical reaction   using ionic liquid solution
  Superconductivity in FeTe0.8S0.2 is successfully induced by an electrochemical reaction using an ionic liquid solution. A clear correlation between the Fe concentration in the solution and the manifestation of superconductivity was confirmed, suggesting that superconductivity was induced by the deintercalation of excess iron. 
Aichi Yamashita, Satoshi Demura, Masashi Tanaka, Keita Deguchi, Takuma   Yamaki, Hiroshi Hara, Kouji Suzuki, Yunchao Zhang, ...
cond-mat.supr-con