Electronic structure and thermal conductivity of zirconium carbide with hafnium additions
Electronic structure and thermal conductivity of zirconium carbide with hafnium additions
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DOI：
10.1111/jace.17860
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发表时间：
2021-05
影响因子：
3.9
通讯作者：
Yue Zhou;W. Fahrenholtz;J. Graham;G. Hilmas
中科院分区：
文献类型：
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作者：
Yue Zhou;W. Fahrenholtz;J. Graham;G. Hilmas
从理论上研究了不同Hf含量的ZrC的晶格热导率。计算了ZrC和（Zr，Hf）C（含3.125或6.25at%Hf）的态密度和电子密度差。结果发现，电子结构并没有显着改变与铪的添加。通过将第一原理计算与Debye-Callaway模型相结合来计算所有组合物的晶格热导率。室温下ZrC的理论晶格热导率为68 W·m-1·K-1。当在ZrC中添加3.125和6.25at%的Hf时，晶格热导率分别降低到18和15 W·m-1·K-1。降低电导率的机制是随着Hf杂质的加入，声学声子的频率降低，从而导致德拜温度和晶格热导率的降低。
The lattice thermal conductivity of ZrC with different Hf contents was investigated theoretically. The density of states and electron density differences were calculated for ZrC and (Zr,Hf)C containing 3.125 or 6.25 at% Hf. It was found that the electronic structure did not change significantly with the Hf additions. Lattice thermal conductivities were calculated for all of the compositions by combining first‐principles calculations with the Debye–Callaway model. The theoretical lattice thermal conductivity of ZrC was 68 W·m−1·K−1at room temperature. When adding 3.125 and 6.25 at% Hf into ZrC, the lattice thermal conductivities decreased to 18 and 15 W·m−1·K−1, respectively. The mechanism for the decreased conductivity is that with the addition of Hf impurities, the frequency of the acoustic phonons decreased, which resulted in decreases in the Debye temperature and lattice thermal conductivity.