Thermoelectric material has attracted more attentions as a promising energy material in recent years. Research nowadays are devoted to improvement of figure-of-merit (zT=S.sup.2T/.rho..kappa.). Motivated by p-type AgSbTe.sub.2 compound, ternary Ag--Sb--Te has been reported as an important thermoelectric system. Although ternary AgSbTe.sub.2 compound has been considered as a candidate for thermoelectric materials with the advantages of low thermal conductivity (.kappa..sub.p=0.6 WK.sup.-1 m.sup.-1), the relatively high electrical resistivity (.rho.=7.5*10.sup.-3 .OMEGA.cm) has limited its applications. This invention disclosed brand-new Ag--Sb--Te bulk materials with very fine microstructures that nanoscale Ag.sub.2Te phase precipitate uniformly in the multi-phase matrix through class I reaction, liquid=Ag.sub.2Te+AgSbTe.sub.2+.delta.. Moreover, the electrical resistivity (.rho.) measured by four-probe method is as low as 8.4*10.sup.-4 (.OMEGA.cm) at room temperature, which guarantees the promise of those ternary bulk materials. |