Thermoelectric properties of Rh-doped Ru2Si3 prepared by floating zone melting method

Precipitation-free samples of Rh-doped Ru2Si3 were prepared by the floating zone (FZ) method. The temperature dependences of the electrical resistivities and the Seebeck coefficients of Rh-doped Ru2Si3 (Rh content=0, 4, 6 mol%) were measured. The electrical resistivities of both 4% and 6% Rh-doped Ru2Si3 were smaller than those of undoped Ru2Si3 prepared by the FZ method and 4% Rh-doped one prepared by other methods. The maximum value of the Seebeck coefficients for all samples was −175 μV/K at 673 K for 4% Rh-doped Ru2Si3. The dimensionless thermoelectric figure of merit reached 0.8 for 4% Rh-doped Ru2Si3 at 1073 K, which was about 50% larger than that of optimized n-type SiGe.