【摘 要】
：
Lattice thermal conductivities of zirconium carbide(ZrCx,x=1,0.75 and 0.5)ceramics with different car-bon vacancy concentrations were calculated using a combination of first-principles calculations and the Debye-Callaway model.The Grüneisen parameters,Deb
【机 构】
：
Department of Materials Science and Engineering,Missouri University of Science and Technology,Rolla,
论文部分内容阅读
Lattice thermal conductivities of zirconium carbide(ZrCx,x=1,0.75 and 0.5)ceramics with different car-bon 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 ZrCx determined using first-principles calculations.In addi-tion,the effects of average atomic mass,grain size,average atomic volume and Zr isotopes on the lattice thermal conductivities of ZrCx were analyzed using phonon scattering models.The lattice thermal con-ductivity decreased as temperature increased for ZrC,ZrC0.75 and ZrC0.5(Zr2C),and decreased as carbon vacancy concentration increased.Intriguingly,ZrCx can be tailored from a thermal conducting material for ZrC with high lattice thermal conductivity to a thermal insulating material for ZrC0.5 with low lattice thermal conductivity.Thus,it opens a window to tune the thermal properties of ZrCx by controlling the carbon vacancy content.
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