Thermoelectric properties of antiperovskite calcium oxides Ca3PbO and Ca3SnO
Thermoelectric properties of antiperovskite calcium oxides Ca3PbO and Ca3SnO
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DOI：
10.1063/1.4952393
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发表时间：
2016-05-28
影响因子：
3.2
通讯作者：
Takenaka, K.
中科院分区：
文献类型：
--
作者：
Okamoto, Y.;Sakamaki, A.;Takenaka, K.
我们报告的热电性能的多晶样品Ca 3 Pb 1-xBixO（x = 0，0.1，0.2）和Ca 3SnO，都在立方反钙钛矿型结构结晶。Ca_3SnO样品具有金属电阻率，室温下其热电势接近100 μ V K ~（-1），导致Ca_3SnO的热电势功率因数大于Ca_3Pb_1-xBi_xO。根据霍尔系数和索末菲系数，Ca_3SnO样品是p型金属，载流子密度接近10（19）cm ~（-3），迁移率接近80 cm ~（-2）V ~（-1）s ~（-1），与简并半导体相当，空穴载流子有效质量也相当大。在Ca 3SnO中观察到的适度高的迁移率和大的有效质量的共存，以及在k空间中的低对称点处可能出现具有小带隙的多路电子结构，表明反钙钛矿Ca氧化物具有作为热电材料的强大潜力。出版社：AIP Publishing
We report the thermoelectric properties of polycrystalline samples of Ca3Pb1-xBixO (x = 0, 0.1, 0.2) and Ca3SnO, both crystallizing in a cubic antiperovskite-type structure. The Ca3SnO sample shows metallic resistivity and its thermoelectric power approaches 100 mu V K-1 at room temperature, resulting in the thermoelectric power factor of Ca3SnO being larger than that of Ca3Pb1-xBixO. On the basis of Hall and Sommerfeld coefficients, the Ca3SnO sample is found to be a p-type metal with a carrier density of similar to 10(19) cm(-3), a mobility of similar to 80 cm(2) V-1 s(-1), both comparable to those in degenerated semiconductors, and a moderately large hole carrier effective mass. The coexistence of moderately high mobility and large effective mass observed in Ca3SnO, as well as possible emergence of a multivalley electronic structure with a small band gap at low-symmetry points in k-space, suggests that the antiperovskite Ca oxides have strong potential as a thermoelectric material. Published by AIP Publishing.