The Synthesis and Thermoelectric Properties of p-Type Li1−xNbO2-Based Compounds
The Synthesis and Thermoelectric Properties of p-Type Li1−xNbO2-Based Compounds
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DOI：
10.1007/s11664-016-5220-z
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发表时间：
2017-01
影响因子：
2.1
通讯作者：
J. Rahman;Eun-Ji Meang;D. Nguyen;W. Seo;A. Hussain;M. Kim;Soonil Lee
中科院分区：
文献类型：
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作者：
J. Rahman;Eun-Ji Meang;D. Nguyen;W. Seo;A. Hussain;M. Kim;Soonil Lee
研究了ap型氧化物材料（Li 1 − xNbO 2，x = 0-0.6）的热电性能。该组合物是在还原性气氛下通过固相反应法合成的。通过电导率和Seebeck系数的测量确定了电荷输运性质。电导率随x值呈非单调变化，随温度升高表现为金属行为，在650 K以上表现为非本征导电为主的温度无关行为。另一方面，塞贝克系数随着温度的升高而增加，并且随着Li空位浓度的增加而逐渐减小，这是通过合成和随着温度逐渐相变到富Li的Li 3 NbO 4相来实现的，并且在高温下在x = 0.6处呈现ann型TE，这归因于Nb取代到Li位点中。由于阳离子无序缺陷和第二相的存在，热导率随温度的升高而单调降低。在低氧分压下的Li空位诱导的Li 1 − xNbO 2基化合物显示出作为热电应用的候选p型材料的前景，特别是对于在低氧分压条件下制备的n型氧化物热电材料的共处理。
We investigated the thermoelectric (TE) properties of ap-type oxide material (Li1−xNbO2, withx= 0–0.6). The composition was synthesized via a solid-state reaction method under a reducing atmosphere. The charge transport properties were determined through the electrical conductivity and Seebeck coefficient measurements. The electrical conductivity was non-monotonically varied withxvalue and showed metallic behavior with increased temperature and above 650 K temperature independent behavior dominated by extrinsic conduction. On the other hand, the Seebeck coefficient was increased with an increase in the temperature, and decreased gradually with an increase in the Li vacancy concentration by both synthesis and gradual phase transition to a Li-rich Li3NbO4phase with temperature and appeared as ann-type TE atx= 0.6 under high temperatures, which was attributed to an Nb substitution into the Li site. The thermal conductivity was monotonically reduced with the increase in temperature due to the cation disorder defects and second phases. The Li vacancy induced Li1−xNbO2-based compounds under low oxygen partial pressure show promise as a candidatep-type material for thermoelectric applications, particularly for co-processing withn-type oxide thermoelectric materials fabricated under conditions of low oxygen partial pressure.