Thermoelectric performance of layered SrxTiSe2 above 300 K
Thermoelectric performance of layered SrxTiSe2 above 300 K
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DOI：
10.1088/0953-8984/26/44/445002
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发表时间：
2014-11-05
影响因子：
2.7
通讯作者：
Gupta, S. K.
中科院分区：
文献类型：
--
作者：
Bhatt, Ranu;Patel, Miral;Gupta, S. K.
在本文中，我们报告了 Sr 插层 TiSe2 在 300 K 以上的热电性能。精细的 X 射线衍射、高分辨率透射电子显微镜和扫描电子显微镜图像显示，沿 (0 0 l) 方向定向良好的多晶晶粒以及样品的分层生长。 TiSe2 中 Sr 的嵌入显示出改进的塞贝克系数 (α) 值，而不会改变多数电荷载流子的极性。观察到热导率 (kappa) 从 3.8 W m K-1 急剧降低至 1.2 W m K-1（在 650 K 时），这是由于：(i) 自然层界面、晶界和晶格缺陷引起的声子散射，以及 (ii) 弱结合 TiSe2 层中插入的 Sr 原子的振动。这导致 SrxTiSe2 (x > 0.1) 在 650 K 时的最大 ZT 接近 0.08，几乎是母体 TiSe2 的两倍。
In this paper we report the thermoelectric performance of Sr intercalated TiSe2 above 300 K. Refined x-ray diffraction, high resolution transmission electron microscopy and scanning electron microscopy images show well oriented polycrystalline grains along a (0 0 l) direction and layered growth of the sample. Intercalation of Sr in TiSe2 shows an improved Seebeck coefficient (alpha) value without altering the polarity of the majority charge carrier. A drastic reduction in the thermal conductivity (kappa) from 3.8 W m K-1 to 1.2 W m K-1 (at 650 K) was observed which is ascribed to the: (i) scattering of the phonon by natural layer interfaces, grain boundaries and lattice defects and (ii) rattling of intercalated Sr atoms among weakly bound TiSe2 layers. This led to the maximum ZT of similar to 0.08 at 650 K for SrxTiSe2 (x > 0.1) which is almost twice as high as the parent TiSe2.