Improvements of thermoelectric properties of clathrate compounds by control of their crystal structures and chemical compositions

通过控制笼形化合物的晶体结构和化学成分来改善其热电性能

• 批准号: 17560618
• 负责人: KISHIMOTO Kengo
• 金额: $ 2.37万
• 依托单位: Yamaguchi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560618/
• 关键词: thermoelectric materials; clathrates; crystal structure; rattling; cationic; クラスレート化合物; キャリア密度最適化; 熱電変換材料; 移動度; 有効質量; 電子構造

We attempted to improve of thermoelectric properties of some clathrate compounds by control of their crystal structures and chemical compositions. The obtained results are mainly as follows:1. We have examined the influences of the kind of filled atoms on thermoelectric properties of n-type germanium clathrates. Firstly, we prepared potassium-filled K_8Ga_8Ge_<38> samples to compare their properties with those of Ba_8Ga_<16>Ge_<30>. Although the K_8Ga_8Ge_<38> had only a half number of Ga atoms for carrier compensation, the K_8Ga_8Ge_38 possessed a lower mobility than that of the Ba_8Ga_<16>Ge_<30>. However, the K_8Ga_8Ge_<38> had a larger effective mass, resulting in a higher power factor at room temperature. This result is consistent with their calculated band structures. Secondly, we prepared mixed clathrate Sr_<8-x>Ba_xGa_<16>Ge_<30> samples with various Ba-to-Sr ratios. Their thermoelectric properties varied systematically with the Ba content x. The electrical conductivity decreas … More ed with the Ba content x, while the activation temperature range and the temperature where the Seebeck coefficient reached the maximum value increased. The results may be associated with the band structures.2. We investigated some cationic clathrates to obtain a, high efficiency p-type thermoelectric material. Firstly, we successfully synthesized iodine-or tellurium-filled cationic clathrate compounds Sn_<38>Sb_8I_8, Ge_<38>Sb_8I_8, Ge_<30>P_<16>Te_8 and Si_<30>P_<16>Te_8 by sintering with mechanical alloying technique. The obtained samples were big in size enough to measure their properties, whereas cationic clathrates prepared by ampoule technique or high pressure technique are small. Secondly, we examined their thermoelectric properties. The obtained cationic clathrates Sn_<38>Sb_8I_8, Ge_<38>Sb_8I_8 and Ge_<30>P_<16>Te_8 possessed as low thermal conductivities as that of anionic clathrates such as Ba_8Ga_<16>Ge_<30> conductivities. Although the iodine-filled clathrates were n-type, the tellurium-filled clathrates Ge_<30>P_<16>Te_8 and Si_<30>P_<16>Te_8 showed p-type conductivity. In addition, the Si_<30>P_<16>Te_8 could be doped with carriers, resulting in a relatively high dimensionless figure of merit ZT of 0.45 for p-type materials. Less

本文试图通过控制笼形化合物的晶体结构和化学组成来改善其热电性能。得到的结果主要如下：1。研究了填充原子种类对n型锗笼形物热电性能的影响。首先，我们制备了K_8Ga_8Ge_3<38>样品，并与Ba_8Ga_Ge_3样品进行了性能比较<16><30>。虽然K_8Ga_8Ge_38中<38>只有一半Ga原子用于载流子补偿，但其迁移率比Ba_8Ga_Ge_38低<16><30>。而K_8Ga_8Ge_3<38>具有较大的有效质量，在室温下具有较高的功率因数。这一结果与计算的能带结构一致。其次，制备了不同Ba/Sr比的混合包合物Sr_<8-x>Ba_xGa_<16>Ge_<30>x样品。它们的热电性能随Ba含量x而系统地变化。电导率降低 ...更多信息 随着Ba含量x的增加，活化温度范围和Seebeck系数达到最大值的温度增加，活化温度艾德增大。这些结果可能与能带结构有关.我们研究了一些阳离子包合物以获得高效的p型热电材料。首先，我们采用机械合金化的方法合成了碘或碲填充的阳离子笼形化合物Sn_<38>Sb_8I_8、Ge_<38>Sb_8I_8、Ge_<30>P_<16>Te_8和Si_<30>P_<16>Te_8。所得到的样品的尺寸大到足以测量其性质，而阳离子包合物制备的技术或高压技术是小的。其次，我们研究了它们的热电性能。所得阳离子包合物Sn_<38>Sb_8I_8、Ge_<38>Sb_8I_8和Ge_<30>P_<16>Te_8具有与阴离子包合物Ba_8Ga_ Ge_8一样低的热导率<16><30>。虽然碘填充的笼形物是n型的，但碲填充的笼形物Ge_<30>P_<16>Te_8和Si_<30>P_<16>Te_8显示p型导电性。此外，Si_<30>P_<16>Te_8可以掺杂载流子，从而导致p型材料的相对高的无量纲优值ZT为0.45。少

项目成果

クラスレート化合物Ba_8Ga_<16>Ge_<30>の作製と熱電気的特性

笼形化合物Ba_8Ga_<16>Ge_<30>的制备及其热电性能

• 发表时间: 2006
• 期刊: 第3回日本熱電学会学術講演会論文集
• 作者: T.Inoue;T.Matsui;N.Fujimura;H.Tsuda;K.Morii;Isao Fujita;Kengo Kishimoto;Kengo Kishimoto;石原剛志;三代俊介
• 通讯作者: 三代俊介

タイプIIIクラスレート化合物Ba_6In_xGe_<25-x>の作製とその熱電気的特性

III型笼形化合物Ba_6In_xGe_<25-x>的制备及其热电性能

• 发表时间: 2006
• 期刊: 第3回日本熱電学会学術講演会論文集
• 作者: T.Inoue;T.Matsui;N.Fujimura;H.Tsuda;K.Morii;Isao Fujita;Kengo Kishimoto;Kengo Kishimoto;石原剛志
• 通讯作者: 石原剛志

クラスレート化合物I_8Sb_8 (Sn, Ge)_<38-x-y>A_xB_y (A=III,B=V)の作製と熱電気的特性

笼形化合物I_8Sb_8(Sn,Ge)_<38-x-y>A_xB_y(A=III,B=V)的制备及热电性能

• 发表时间: 2005
• 期刊: 第2回日本熱電学会学術講演会論文集
• 作者: Kengo Kishimoto;Koji Akai;Noriaki Muraoka;Tsuyoshi Koyanagi;Mitsuru Matsuura;Kengo Kishimoto;石原剛志;赤井光治;Kengo Kishimoto;Isao Fujita;村岡徳章
• 通讯作者: 村岡徳章

Preparation and thermoelectric properties of sintered iodine-containing clathrate compounds Ge38Sb8I8 and Sn38Sb8I8

• DOI: 10.1063/1.2209207
• 发表时间: 2006-06
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: K. Kishimoto;Shuntaro Arimura;T. Koyanagi

タイプIIIクラスレート化合物Ba_6In_2Ge_<25-x>の作製とその熱電気的特性

III型笼形化合物Ba_6In_2Ge_<25-x>的制备及其热电性能

• 发表时间: 2006
• 期刊: 第3回日本熱電学会学術講演会論文集
• 作者: Kengo Kishimoto;Koji Akai;Noriaki Muraoka;Tsuyoshi Koyanagi;Mitsuru Matsuura;Kengo Kishimoto;石原剛志
• 通讯作者: 石原剛志