Thermoelectric Properties of p‐ and n‐ type Eu 5 Sn 2 As 6
Thermoelectric Properties of p‐ and n‐ type Eu 5 Sn 2 As 6
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p-型和n-型Eu 5 Sn 2 As 6 的热电性能
DOI：
10.1002/zaac.202100386
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Kauzlarich, Susan M.
中科院分区：
文献类型：
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作者：
Devlin, Kasey P.;Gomez, Braulio;Kauzlarich, Susan M.
Eu 5Sn 2As 6是一种Zintl相，在正交空间群PbAm中结晶，具有c-方向的SnAs 4四面体的一维链。Eu 5Sn 2As 6具有令人印象深刻的室温Seebeck>100 μV/K，600 K时< - 100 μV/K，与650 K时的Mp-ton-type交叉。 Eu 5Sn 2As 6的最大热电优值zT很小（0.075），与Zintl相Ca 5Al 2Sb 6的热电优值zT相当，后者的热电性能通过在Ca位上掺杂Na而得到改善.在本研究中，我们发现，Eu_5Sn_2As_6的热电性能可以通过K或La的替代而得到改善。系列Eu 5-xKxSn 2As 6提供了最大zT的增加0.22（对于x =0.15），这是由于电阻率降低，而双极导电的开始温度系统地增加。在300-800 K的温度范围内，Eu 5-xLaxSn 2As 6取代La后，形成一种新的Zintl相。
Eu5Sn2As6is a Zintl phase crystalizing in the orthorhombic space groupPbamwith one‐dimensional chains of corner‐shared SnAs4tetrahedra running in thec‐direction. Eu5Sn2As6has an impressive room temperature Seebeck of >100 μV/K and < – 100 μV/K at 600 K crossing fromp‐ ton‐type at 650 K. The maximum thermoelectric figure of merit,zT, for Eu5Sn2As6is small (0.075), comparable to that of the Zintl phase Ca5Al2Sb6whose thermoelectric performance was improved by doping Na onto the Ca sites. In this study, we show that the thermoelectric properties of Eu5Sn2As6can be improved by substituting with K or La. The series Eu5‐xKxSn2As6provides an increase in maximumzTof 0.22 forx=0.15 due to a decrease resistivity while the onset of bipolar conduction systematically increases in temperature. Upon La substitution, Eu5‐xLaxSn2As6results in a newn‐type Zintl phase across the temperature range of 300–800 K.