The anisotropic resistivity (pab(T) and pc(T)) and thermoelectric power (Sab(T) and Sc(T)) of HgBr2-intercalated Bi-2212 single crystals are measured. In the normal state (T > Tc), the semiconductor-like behaviour of pc(T) of the pristine Bi2Sr2CaCu2Oy becomes metallic upon HgBr2 intercalation, while pab(T) remains metallic. Unlike the iodine-intercalated Bi-2212, the semiconductor-like Sab(T) of the pristine sample changes to be weakly temperature dependent upon HgBr2 intercalation and yet the SC(T) remains temperature independent. Resistivity and thermoelectric power data of the HgBr2-intercalated samples show anomalies at T = 250 K reminiscent of a phase transition. The results indicate that the charge transfer from HgBr2 to the CuO2 plane is important, which supports the picture that the doping-induced holes in the copper oxide sheets are responsible for the high-temperature superconductivity.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Condensed Matter Physics
- Metals and Alloys
- Materials Chemistry
- Electrical and Electronic Engineering