采用溶胶凝胶法合成Ca_(3-x)Yb_xCo_4O_(9+δ)(x=0,0.15,0.30,0.45)化合物粉体,以粉体为原料结合放电等离子烧结(Spark Plasma Sinte-ring,SPS)制备出致密的块体材料.研究了Yb掺杂对热电化合物电传输特性的影响.结果表明:在300～850K温度范围内,每个样品的See-beck系数又随着温度的升高而单调增大,而Yb取代Ca可使材料的电阻率(ρ)和Seebeck系数同时增加,这是因为三价的Yb~(3+)取代二价的Ca~(2+)将使化合物的载流子浓度降低,当x=0.30时,材料的功率因子最佳,850K时达到0.32×10~(-3)W·K~(-2)·m~(-1).
The powder of Ca_(3-x)Yb_xCo_4O_(9+δ)(x =0, 0.15, 0.30, 0.45) was synthesized by using sol-gel process and bulk samples were prepared by SPS sintering. The electric transmission properties were carefully studied from 300 to 850 K. The results indicated that the Seebeck coefficient of each sample increased with increasing temperature. The substitution of Yb~(3+) for Ca~(2+) resulted in the in-crease of both Seebeck coefficient and electric resistivity, which could be attributed to the decrease of carrier concentration. When x = 0.3, the maximal power factor reached 0.32 × 10~(-3) W·K~(-2)·m~(-1) at 850 K.
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