氟掺杂对Ca_3Co_4O_9化合物微观结构和热电性能的影响(英文)

EFFECT OF FLUORINE DOPING ON MICROSTRUCTURE AND THERMOELECTRIC PROPERTIES OF Ca_3Co_4O_9 COMPOUND

采用固相合成法及放电等离子烧结制备了Ca3Co4(FxO1-x)9(x=0,0.01,0.02)块体样品,系统研究了氟(F)掺杂对Ca3Co4O9微观结构和热电性能的影响。结果表明:F掺杂样品均为单一化合物。在300～900K,与纯样相比,F掺杂样品的Seebeck系数变化较小,电导率显著增大,热导率先减小后随F掺量的增加而增大。x=0.01时,样品具有最高电导率和最低热导率,分别为14×103S/m和2.16W/(m·K)。在900K,样品最大热电优值(ZT值)为0.16,较纯样品的提高了近100%。

Ca3Co4（FxO1–x） 9（x = 0,0.01,0.02） polycrystalline samples were prepared by the solid-state synthesis method and spark plasma sintering,and effect of fluorine（F） doping on the microstructure and thermoelectric properties of Ca3Co4O9 were systemati-cally researched. The results show that F-doped samples are both single compound. In comparison with the pure sample between 300 K and 900 K,the Seebeck coefficients of F-doped samples change little,electrical conductivities increase obviously,and the thermal conductivities decrease at first but increase with further F addition. The sample with x= 0.01 has the highest electrical conductivity and lowest thermal conductivity, which are 14× 10^3 S/m and 2.16 W/（m-K）, respectively. At 900 K, the sample x = 0.01 has the maximum dimensionless figure of merit （ZT） value of 0.16, which is nearly100% greater than that of the pure sample.