Bulk superconductivity in single phase Bi3O2S3
  We report the synthesis of single phase Bi3O2S3 sample and confirm the occurrence of bulk superconductivity with transition temperature at 5.8 K. The Bi3O2S3 super-conductor is categorized as the typical type-II supercon-ductor based on the results of both temperature and mag-netic field dependences of magnetization. Hall coefficient measurements give evidence of a multiband character, with a dominant conduction mainly by electron-like charge carriers. The charge carrier density is about 1.45 X 1019 cm3, suggesting that the system has very low charge carrier density. 
Jifeng Shao, Zhongheng Liu, Xiong Yao, Li Pi, Shun Tan, Changjin   Zhang, and Yuheng Zhang
cond-mat.supr-con