Transport Properties of an Intermetallic with Pseudo-hollandite Structure as a Potential Thermoelectric Material: The Example of TlxCr5Se8

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• 作者：Hidefumi Takahashi ; Nunna Raghavendra ; Franck Gascoin ; Denis Pelloquin ; Sylvie H茅bert ; Emmanuel Guilmeau
• 刊名：Chemistry of Materials
• 出版年：2013
• 出版时间：May 14, 2013
• 年：2013
• 卷：25
• 期：9
• 页码：1809-1815
• 全文大小：383K
• 年卷期：v.25,no.9(May 14, 2013)
• ISSN：1520-5002

文摘

The transport properties of Tl_xCr₅Se₈ pseudo-hollandite have been investigated, from 2 up to 800 K. A semiconducting behavior is observed from 200 down to 2 K, with a transition observed at T 43 K, at the antiferromagnetic transition. Above 200 K, small values of 蟻 are obtained, close to 10 m惟路cm at 800 K. The Seebeck coefficient continuously increases in this range of temperature, reaching 300 渭V/K at 800 K. Moreover, the thermal conductivity of this low dimensional structure is small, leading to a figure of merit ZT = S²T/(蟻魏) = 0.5 at 800 K. All the electronic transport properties can be fitted by a standard Boltzmann equation, with a large scattering parameter (r = 3/2, characteristic of diffusion by ionized impurities). The combination of small thermal conductivity, large scattering parameter, and low concentration of carriers (4.5 脳 10¹⁹ cm^鈥?) is at the origin of this large ZT.

Keywords:

hollandite; thermoelectric; chalcogenides; low thermal conductivity; selenides