Bandgap narrowing in the layered oxysulfide semiconductor Ba3Fe2O5Cu2S2: Role of FeO2 layer

Bandgap narrowing in the layered oxysulfide semiconductor Ba₃Fe₂O₅Cu₂S₂: Role of FeO₂ layer

Zhang Han¹, Jin Shifeng^{1, †,}, Guo Liwei¹, Shen Shijie¹, Lin Zhiping¹, Chen Xiaolong^{1, 2}

(a) Zero field cooling (ZFC) and field cooling (FC) χ(T) data taken in an applied field of 2 kOe. The fit to the Curie–Weiss law is shown as a green line. Inset: the M–H curves at 10 K. (b) Temperature dependence of specific heat C_p(T) of Ba₃Fe₂O₅Cu₂S₂ from 10 K to 300 K.