Fe对Ce_yFe_xCo_(4-x)Sb_(12)化合物结构和热电传输性质的影响

EFFECT OF Fe CONTENT ON THE CRYSTAL STRUCTURE AND THE THERMOELECTRIC TRANSPORT PROPERTIES OF Ce_yFe_xCo_(4-x)Sb_(12)

用熔融法合成了单相填充式skutterudite化合物CeyFexCo4 -xSb12 (x =0— 3 0 ,y =0— 0 74) .对Ce的填充范围 ,置换Fe原子对化合物的结构及热电传输特性的影响进行了研究 ,Ce的填充分数随Fe含量的增加而线性增加 ,当Fe含量大约为 3时 ,Ce的填充分数达到 0 74.晶格常量a随Fe含量的增加而增加 ,Ce的填充使晶格常量进一步增加 .当Ce填充分数达到饱和状态时 ,CeyFexCo4 -xSb12 化合物表现为 p型传导 ,霍尔系数RH 随Fe含量的增加而降低 ,空穴浓度 p和电导率σ随Fe含量的增加而增加 ,泽贝克系数α随Fe含量的增加而降低 .当Fe/Co比大约为 1 5 / 2 5时 ,CeyFexCo4 -xSb12 的晶格热导率 (κl)达到最小值 .

Single\|phase filled skutterudite compounds,Ce y Fe x Co 4-x Sb 12 ( x=0—3 0,y=0—0 74 ),were synthesized by a melting method.Effect of Fe content on Ce filling fraction,the crystal structure and the thermoelectric transport properties of Ce y Fe x Co 4-x Sb 12 saturated by Ce were investigated.Ce filling fraction increased linearly with increasing Fe content.The lattice constants a of Ce y Fe x Co 4-x Sb 12 increased with increasing Fe content and Ce filling fraction.All samples showed p\|type conduction.Hall coefficient R H decreased with increasing Fe content.Hole concentration p and electrical conductivity σ increased with increasing Fe content.Seebeck coefficient α decreased with increasing Fe content.While Fe/Co ratio was about 1.5/2.5,the lattice thermal conductivity ( κ l) reached the minimum values.