From thermal conductive to thermal insulating: Effect of carbon vacancy content on lattice thermal conductivity of ZrC
From thermal conductive to thermal insulating: Effect of carbon vacancy content on lattice thermal conductivity of ZrC
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DOI：
10.1016/j.jmst.2020.11.068
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发表时间：
2021-08
影响因子：
10.9
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
采用第一性原理计算和德拜-卡拉韦模型相结合的方法，计算了不同碳空位浓度的碳化锆( x，x=0.75和0.5)陶瓷的晶格导热系数。用第一性原理计算得到了由声子色散得到的Grüneisen参数、德拜温度和声子群速度。此外，还利用声子散射模型分析了平均原子质量、晶粒度、平均原子体积和Zr同位素对ZrCx晶格热导率的影响。晶格热导率随温度的升高而降低，随碳空位浓度的增加而降低。有趣的是，ZrCx可以从高晶格导热系数的ZRC导热材料到低晶格导热系数的ZrC0.5绝热材料。因此，它打开了一个窗口，通过控制碳空位含量来调节ZrCx的热性能。
Lattice thermal conductivities of zirconium carbide (ZrCx,x= 1, 0.75 and 0.5) ceramics with different carbon vacancy concentrations were calculated using a combination of first-principles calculations and the Debye-Callaway model. The Grüneisen parameters, Debye temperatures, and phonon group velocities were deduced from phonon dispersions of ZrCxdetermined using first-principles calculations. In addition, the effects of average atomic mass, grain size, average atomic volume and Zr isotopes on the lattice thermal conductivities of ZrCxwere analyzed using phonon scattering models. The lattice thermal conductivity decreased as temperature increased for ZrC, ZrC0.75and ZrC0.5(Zr2C), and decreased as carbon vacancy concentration increased. Intriguingly, ZrCxcan be tailored from a thermal conducting material for ZrC with high lattice thermal conductivity to a thermal insulating material for ZrC0.5with low lattice thermal conductivity. Thus, it opens a window to tune the thermal properties of ZrCxby controlling the carbon vacancy content.