Microstructural control and thermoelectric properties of misfit layered sulfides (LaS)1+ mTS2 (T = Cr, Nb): The natural superlattice systems

Priyanka Jood, Michihiro Ohta, Hirotaka Nishiate, Atsushi Yamamoto, Oleg I. Lebedev, David Berthebaud, Koichiro Suekuni, Masaru Kunii

研究成果: Contribution to journalArticle査読

27 被引用数 (Scopus)

抄録

We investigated the high-temperature thermoelectric properties of misfit layered n-type (LaS)1.20CrS2 and p-type (LaS) 1.14NbS2. The samples were prepared by CS2 sulfurization of 6 or 12 h duration and then consolidated using pressure-assisted sintering to produce randomly and highly oriented samples whose microstructures were tunable. Transmission electron microscopy analysis showed that perfectly layered structures containing some stacking faults had formed. The randomly and highly oriented natural superlattices provided ultralow lattice thermal conductivities (as low as ∼0.9 and ∼0.5 W K -1 m-1, respectively, at 950 K) perpendicular to the pressing axis. The improved electrical conductivities of the oriented CrS 2 and NbS2 samples resulted in high power factors of 170 and 410 μW K-2 m-1, respectively. The highly oriented texture produced the highest thermoelectric figure of merit ZT of 0.14 at 950 K among the (LaS)1.20CrS2 system, whereas the weakly/randomly oriented texture produced the highest ZT of 0.15 at 950 K among the (LaS)1.14NbS2 system. These misfit layered sulfides exhibit phonon glass-electron crystal behavior and provide tremendous opportunities for further enhancing ZT by optimizing the thermoelectric properties.

本文言語英語
ページ(範囲)2684-2692
ページ数9
ジャーナルChemistry of Materials
26
8
DOI
出版ステータス出版済み - 4 22 2014
外部発表はい

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

フィンガープリント 「Microstructural control and thermoelectric properties of misfit layered sulfides (LaS)<sub>1+ m</sub>TS<sub>2</sub> (T = Cr, Nb): The natural superlattice systems」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

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