Abstract
A series of polycrystalline samples of Mg
1−
x
Pb
x
B
2 (0≤
x≤0.10) were prepared by a solid state reaction method and their structure, superconducting transition temperature and transport properties were investigated by means of X-ray diffraction (XRD) and resistivity measurements. Mg
1−
x
Pb
x
B
2 compounds were shown to adopt an isostructural AlB2-type hexagonal structure in a relatively small range of lead concentration,
x≤0.01. The crystalline lattice constants were evaluated and were found to exhibit slight length compression as
x increases. The superconducting transition temperature (
T
c) steadily decreases with Pb doping. It is suggested that the mechanism of superconductivity reduction by lead doping can be attributed to the chemical pressure effect.