抄録
An average figure of merit value of Z-10-3K-1 was achieved for CoSb3 substituted by Pd (3%) over the wide temperature range 300-800K. Samples of (PdxCo1-x) Sb3 compounds, 0≤x≤0.05, were prepared by static iso-thermal pressing (SIP) the milled powders and by subsequent annealing in inert gas. Measurements of the electrical and thermal transport properties were made on the samples at temperatures ranging from 300K to 800K. It was found that the conduction type was n-type and the electron mobility as high as-100cm2/(Vs) was obtained for a (Pd0.03Co0.97) Sb3 sample. The high value of the mobility can be attributed to the valence band that is only formed by p-p bonds between adjacent Sb-atoms. The doping of Pd into CoSb3 lattice causes the type conversion from p-type to n-type, and results in a high Seebeck coefficient of S--0.3mV/K, electrical conductivity σ-3×102 S/cm, and low thermal conductivity k-2.5W/(mK) at room temperature.
