Thermoelectric properties of the Ru2Ni2Sb12 ternary skutterudite

► Skutterudite-type structure with space group Im3¯ of the Ru2Ni2Sb12 was confirmed. ► The band gap of the studied compounds was estimated - Eg∼0.06 eV. ► Low lattice thermal conductivity of the Ru2Ni2Sb12 was observed.