Enhancement of thermoelectric figure of merit in binary-phased La_(0.3)Ce_(0.37)Fe_3CoS_(12)-PbTe materials

摘要

To enhance the Seebeck coefficient and reduce the thermal conductivity while maintaining a satisfied electrical conductivity, a disordered structure was introduced into the La_(0.3)Ce_(0.37)Fe_3CoSb_(12) crystalline by adding a low-melting-point lead telluride (PbTe). The results suggest that the disordered structure created by the melted PbTe at 870 K can be partly preserved into the La_(0.3)Ce_(0.37)Fe_3CoSb_(12) materials at room temperature. With the existence of the disordered structure the Seebeck coefficient at 773 K is increased from 143 μV K~(-1) to 265 μV K~(-1) while the thermal conductivity is reduced from 2.12 W m~(-1) K~(-1) to 1.60 W m~(-1) K~(-1) nevertheless the electrical conductivity is dropped from 78,000 Ω~(-1) m~(-1) to 23,500 Ω~(-1) m~(_1). A figure of merit of 0.95 at 773 K is observed for the material containing 40% PbTe.