2018 年 126 巻 7 号 p. 591-593
The layered compound Bi2(O,F)S2 is synthesized by NaF treatment. Heat treatment of Bi2OS2 with different amounts of NaF powder at 400°C produces Bi2(O,F)S2 superconductors. NaF is low-cost and stable fluorination sources when it is compared with other sources. NaF treatment increased the a-axis of Bi2(O,F)S2. Maximum superconducting transition temperature of obtained Bi2(O,F)S2 is 4.7 K.