Thermoelectric properties of Ba/sub 8/Ga/sub x/Ge/sub 46-x/ clathrate compounds
Thermoelectric properties of Ba/sub 8/Ga/sub x/Ge/sub 46-x/ clathrate compounds
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Ba/sub 8/Ga/sub x/Ge/sub 46-x/笼形化合物的热电性能
DOI：
10.1109/ict.2002.1190269
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
K. Matsubara
中科院分区：
文献类型：
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作者：
H. Anno;M. Hokazono;M. Kawamura;J. Nagao;K. Matsubara
采用电弧熔炼和放电等离子烧结技术生长了不同Ga组分（名义x=12-20）的Ba/sub 8/Ga/sub x/Ge/sub 46-x/笼形化合物多晶，研究了Ga组分对热电性能的影响。化合物的导电载流子类型由n型（x=12-16）转变为p型（x=17-20）。改变Ga组分可以成功地控制载流子浓度。的（绝对）塞贝克系数值为p型化合物被发现是大于那些为n型化合物。n型和p型化合物的晶格热导率值都非常低（/spl sim/0.01 W/cmK）。对于n型（x=15）和p型（x=18）化合物，估计的热电优值ZT值达到/spl sim/1。因此，通过优化Ga组分可以显著提高Ba/sub 8/Ga/sub x/Ge/sub 46-x/笼形化合物的热电性能。
Polycrystalline Ba/sub 8/Ga/sub x/Ge/sub 46-x/ clathrate compounds with different Ga compositions (nominal x=12-20) have been grown by arc melting and spark plasma sintering techniques and the effects of Ga composition on the thermoelectric properties have been investigated. The conduction carrier type of the compounds altered from n-type (x=12-16) to p-type (x=17-20). Varying the Ga composition could successfully control the carrier concentration. The (absolute) Seebeck coefficient values for p-type compounds were found to be larger than those for n-type compounds. The lattice thermal conductivity values for both n- and p-type compounds were extremely low (/spl sim/0.01 W/cmK). The estimated thermoelectric figure of merit ZT values reach /spl sim/1 for both n-type (x=15) and p-type (x=18) compounds. Therefore, it was found that the thermoelectric properties of Ba/sub 8/Ga/sub x/Ge/sub 46-x/ clathrate compounds could be significantly improved by optimizing the Ga composition.