Crystal Structure and Thermoelectric Properties of β-Pyrochlore-Type Alkali Iron Tungsten Oxides with Cage-Like Structure
Crystal Structure and Thermoelectric Properties of β-Pyrochlore-Type Alkali Iron Tungsten Oxides with Cage-Like Structure
复制标题
笼状结构β-烧绿石型碱金属钨氧化物的晶体结构和热电性能
DOI：
10.1007/s11664-015-4179-5
复制
发表时间：
2016
影响因子：
2.1
通讯作者：
Michitaka Ohtaki
中科院分区：
文献类型：
--
作者：
Kohei Mizuta;Michitaka Ohtaki
We report the electrical and thermal properties ofβ-pyrochlore (defect pyrochlore) oxidesAFe0.33W1.67O6(A= K, Rb, Cs) with a crystal structure having a small cation surrounded by oversized cage-like framework. The thermal conductivity,κ, of CsFe0.33W1.67O6and RbFe0.33W1.67O6showed extremely low values as oxides (below 1.0 W/mK) similar to those ofATaWO6(A= K, Rb, Cs) which we have already reported. These lowκvalues are ascribed to a “rattling” motion of theAcations, evidenced by their crystal structure refinement and the Raman spectra. Their electrical conductivity,σ, was in the order of 10−3S/cm, and the Seebeck coefficient,S, was −500 to −600μV/K. The electrical conductivity ofAFe0.33W1.67O6(A= Rb, Cs) was much higher than those ofATaWO6(A= Rb, Cs), suggesting that an appropriate selection of the framework composition enables us to have better thermoelectric performance.
