Influence of preparation conditions on thermoelectric properties of Ba8Ga16Si30 clathrate by combining arc melting and spark plasma sintering methods
Influence of preparation conditions on thermoelectric properties of Ba8Ga16Si30 clathrate by combining arc melting and spark plasma sintering methods
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电弧熔炼与放电等离子烧结相结合制备条件对Ba8Ga16Si30包合物热电性能的影响
DOI：
10.1088/1742-6596/379/1/012007
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
Masahiro Hokazono and Ritsuko Shirataki
中科院分区：
文献类型：
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作者：
Hiroaki Anno;Hiroki Yamada;TakahiroNakabayashi;Masahiro Hokazono and Ritsuko Shirataki
研究了采用电弧熔炼和放电等离子烧结相结合的方法在不同条件下制备的Ba 8 Ga 16 Si 30包合物样品的热电性能。样品的载流子浓度从10 21 cm-3到10 20 cm-3的数量级大幅降低，这是由于通过改变电弧熔化条件来增加Ga含量。因此，塞贝克系数增加，导热率降低，而导电率降低。的有效质量，载流子迁移率和晶格热导率的分析确定使用一个单一的抛物线带模型与合金无序和声子散射机制。对于约6× 10 20 cm-3（RT）的载流子浓度，热电优值系数ZT显著增加至约0.55（900 K）。模拟结果表明，在Ba 8 Ga 16 Si 30系统中，当载流子浓度为2× 1020 cm-3时，ZT可达到0.8（900 K）。
We have investigated the thermoelectric properties of clathrate samples with a nominal Ba 8 Ga 16 Si 30 composition, prepared by combining arc melting and spark plasma sintering methods under different conditions. The carrier concentration of the samples greatly decreases from the order of 10 21 cm− 3 to 10 20 cm− 3 due to an increase in Ga content by changing the arc melting conditions. Consequently, the Seebeck coefficient increases and the thermal conductivity decreases while the electrical conductivity decreases. The effective mass, carrier mobility and lattice thermal conductivity are determined from an analysis using a single parabolic band model with alloy disorder and phonon scattering mechanisms. The thermoelectric figure of merit ZT significantly increases up to about 0.55 (900 K) for a carrier concentration of about 6× 10 20 cm− 3 (RT). The simulation predicts that ZT can reach 0.8 (900 K) at the optimum carrier concentration (about 2× 10 20 cm− 3) in the Ba 8 Ga 16 Si 30 system.