Ca和Ce双原子复合填充p型Ca_mCe_nFe_xCo_(4-x)Sb_(12)化合物的合成及热电性能

Synthesis and thermoelectric properties of dual-atom filled p-type Ca_mCe_nFe_xCo_(4-x)Sb_(12) compounds

用高温熔融法合成了Ca和Ce复合填充的单相p型CamCenFexCo4-xSb12化合物,探索了两种原子复合填充对其热电性能的影响规律.研究结果表明,填充分数相同时,Ca和Ce两种原子复合填充的p型CamCenFexCo4-xSb12化合物的载流子浓度和电导率介于Ca或Ce一种原子单独填充的化合物之间,且随两种原子填充分数m+n的增加而降低;赛贝克系数随两种原子填充总量,尤其是Ce填充分数m的增加以及温度的上升而增加;在相同填充分数时,两种原子复合填充的p型CamCenFexCo4-xSb12化合物的晶格热导率较Ca或Ce一种原子单独填充的化合物的晶格热导率低,当总填充分数m+n为0.3左右,且Ca和Ce的填充量大致相等时,化合物的晶格热导率最低.p型Ca0.18Ce0.12Fe1.45Co2.55Sb12.21化合物的最大热电性能指数ZT值在750K时达到1.17.

The single-phase dual-atom filled p-type CamCenFexCo4-xSb12 compounds were synthesized by melting reaction method. Effects of Ca and Ce filling fraction on the thermoelectric properties of the p-type CamCenFexCo4-xSb12 were investigated. Our results indicate that with the same filling fraction, carrier concentration and electrical conductivity of p-type CamCenFexCo4-xSb12 intervene between that of single atom filled compounds CamFexCo4-xSb12 and CenFexCo4-xSb12, and decreased with increasing Ca and Ce, especially Ce, filling fraction. With the same filling fraction, the lattice thermal conductivity of CamCenFexCo4-xSb12 is smaller than that of CamFexCo4-xSb12 and CenFexCo4-xSb12. Furthermore, when the total filling fraction （m ＋ n） is about 0.3 and the filling fractions of Ca and Ce are approximately equal, the lattice thermal conductivity is the smallest. The greatest ZT value of 1.17 was obtained at 750K for p-type Ca0.18Ce0.12Fe1.45Co2.55Sb12.21.