Preparation and Enhanced Thermoelectric Properties of p-Type BaFe_(12)O_(19)/CeFe_3CoSb_(12) Magnetic Nanocomposite Materials

摘要

A series of p-type xBaFe_(12)O_(19)/CeFe_3CoSb_(12) (x = 0, 0.05%, 0.10%, 0.20%, 0.40%) magnetic nanocomposite thermoelectric (TE) materials have been prepared by the combination of ultrasonic dispersion and spark plasma sintering (SPS). The effects of BaFe_(12)O_(19) magnetic nanoparticles on the phase composition, microstructure, and TE properties of the nanocomposite materials were investigated in this work. x-Ray diffraction analysis shows that all the SPSed bulk samples are composed of main phase skutterudite besides a small amount of FeSb_2 and Sb. The TE transport measurements demonstrated that remarkable enhancements in electrical conductivity and Seebeck coefficient can be simultaneously realized by optimizing the doping content of BaFe_(12)O_(19) magnetic nanoparticles. The lattice thermal conductivity was significantly reduced because of enhanced phonon scattering induced by BaFe_(12)O_(19) nanoparticles. The highest ZT value reached 0.75 at 800 K for the sample with x = 0.05%, increased by 41.5% as compared with that of p-type CeFe_3CoSb_(12) bulk material without BaFe_(12)O_(19) magnetic nanoparticles. This work confirms that doping a small amount of BaFe_(12)O_(19) magnetic nanoparticles can significantly improve the ZT value of p-type xBaFe_(12)O_(19)/CeFe_3-CoSb_(12) magnetic nanocomposite TE materials.