Inducement of superconductivity in Fe(Te,S) by sulfuric acid treatment

Superconductivity of Fe0.95Te0.85S0.15 was induced and enhanced by immersing the as-grown (non-superconducting) sample into sulfuric acid. Dissolved Fe was detected in the sulfuric acid treatment, indicating that excess Fe was removed from the Fe0.95Te0.85S0.15 sample.