  A polycrystalline sample of the high-entropy-alloy-type telluride
AgInSnPbBiTe5 was synthesized using high-pressure synthesis. Superconductivity
with a transition temperature (Tc) of 2.6 K was observed in AgInSnPbBiTe5.
Elemental and structural analyses revealed that five metals are mixed in a
metal site of an NaCl-type structure. Since AgInSnPbBiTe5 has a cation site
(Ag, In, Sn, Pb, and Bi) and an anion site (Te), this is the first example of a
high-entropy-alloy (HEA) pseudo-binary superconductor.
