Influence of Pb doping on superconductivity of α-BiPd and β-Bi2Pd alloys.

Graphical abstract Highlights • Two series of Pb substituted α-Bi 1-x Pb x Pd and β-Bi 2-x Pb x Pd were successfully synthesized by facile solid-state method. • Bi 1-x Pb x Pd (0 ≤ x ≤ 0.2) and Bi 2-x Pb x Pd (0 ≤ x ≤ 0.5) samples show bulk superconductivity and T c monotonically change as increases of Pb content. • One can see that the cell volume has also shown a monotonous decreasing change with higher Pb content for both alloys, which can be attributed to the slightly smaller atomic radius of Pb (1.75 Å) than Bi (1.82 Å). Abstract A series of Pb-doped Bi-based alloys, α-Bi 1-x Pb x Pd (0 ≤ x ≤ 0.5) and β-Bi 2-x Pb x Pd (0 ≤ x ≤ 0.6), were synthesized by facile solid-state reaction method. The powder X-ray diffraction confirmed that the crystal structure of samples remained the same after Pb-doping and the cell volume decreased with increasing Pb content. The influence of Pb-doping effect on superconductivity of BiPd and Bi 2 Pd alloys has been systematically examined by the magnetic susceptibility and resistivity measurements. Both alloy systems have shown bulk superconductivity and metallic conductivity in normal state. Furthermore, the superconducting onset temperature (T c) gradually decreased with higher Pb content for both systems. The T c dropped from 3.7 K for BiPd to 2.7 K for Bi 0.8 Pb 0.2 Pd, whereas the T c dropped from 5.3 K for Bi 2 Pd to 2.4 K for Bi 1.5 Pb 0.5 Pd. [ABSTRACT FROM AUTHOR]