Effect of Ca doping on superconducting properties of Bi4O4S3

We report the transport and magnetic properties of Bi4-xCaxO4S3 (0< x <1) samples. From the obtained results it is found that superconducting transition temperature, Tc increases with 0.25% Ca doping at Bi site, further increase in Ca doping deteriates the superconducting property. The results reveals that 1% of Ca doped sample shows no superconducting transition but a strong semiconducting behavior at below 100K. The effect of structural changes due to Ca doping on superconducting properties were studied.