论文标题
对热电应用中的电子和声子传输的调查
Investigation of electron and phonon transport in Bi-doped CaMnO$_3$ for thermoelectric applications
论文作者
论文摘要
通过热电传输测量，拉曼光谱和第一原则计算，研究了CAMNO3及其BI-Dopart及其BI-DOPART的电子和声子传输。特别是，我们专注于CAMNO3和BI0.03CA0.97MNO3的电子结构，依赖温度的电子和声子寿命及其声速。我们发现，抗铁磁绝缘子CAMNO3破坏了Wiedemann-Franz（WF）定律，Lorenz的数量达到了室温下普通金属的四倍。 Bismuth掺杂降低了CAMNO3的电阻率和塞贝克系数，因此它恢复了WF法律行为。拉曼光谱法证实BI0.03CA0.97MNO3具有较低的Debye频率以及较短的声子寿命。结果，由于导热率较低和电子电阻率，BI0.03CA0.97MNO3在原始CAMNO3上表现出优质的热电特性。
Electron and phonon transports in CaMnO3 and its Bi-doped counterpart, Bi0.03Ca0.97MnO3, are investigated by thermoelectric transport measurements, Raman spectroscopy, and first-principles calculations. In particular, we focus on CaMnO3 and Bi0.03Ca0.97MnO3's electronic structures, temperature-dependent electron and phonon lifetimes, and their sound velocities. We find that the anti-ferromagnetic insulator CaMnO3 breaks the Wiedemann-Franz (WF) law with the Lorenz number reaching four times that of ordinary metals at room temperature. Bismuth doping reduces both the electrical resistivity and the Seebeck coefficient of CaMnO3, thus it recovers the WF law behavior. Raman spectroscopy confirms that Bi0.03Ca0.97MnO3 has a lower Debye frequency as well as a shorter phonon lifetime. As a result, Bi0.03Ca0.97MnO3 exhibits superior thermoelectric properties over the pristine CaMnO3 due to the lower thermal conductivity and electronic resistivity.
