  We succeed in enhancement of a superconducting transition temperature (Tc)
for NdO0.7F0.3BiS2 single crystal by partial substitution of Pb for Bi. The Tc
increases with increasing Pb concentration until 6%. The maximum Tczero is 5.6
K, which is the highest value among BiS2 based superconductors synthesized
under an ambient pressure. Pb substitution for Bi induces lattice shrinkage
along the c axis. These results reflect that superconductivity in this system
is responsive to the lattice strain.
