Synergistic effects of Bi Deficiencies and Fe-doping on the thermoelectric properties and hardness of BiCuSeO ceramics

抄録

Bi_1−xCuSeO + x Fe (x = 0, 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, and 0.12) ceramics have been prepared by mechanical alloying and resistance pressing sintering process, and the synergistic effects of Bi Deficiencies and magnetic Fe doping on the thermoelectric properties and hardness of BiCuSeO ceramics have been investigated in detail. The results indicate that the band gap of the doped sample has narrowed down, which could be confirmed by the infrared absorption spectra. This leads to the dramatical increase of carrier concentration. The corresponding electrical conductivity increases significantly. The Seebeck coefficient decreases, but maintains high values in the high temperature zone. The maximum power factor of 0.38 m Wm⁻¹ K⁻² and ZT of 0.76 were obtained for the Bi_0.92CuSeO + 8% Fe sample at 873 K, which was ∼1.4 and ∼1.3 times as that of the pristine BiCuSeO. The hardness of pristine BiCuSeO is up to 200.0 HV, and increases greatly with the increase of x for solid solution strengthening.