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arXiv · 1806.08557

Ab initio lattice thermal conductivity of bulk and thin-film $\alpha$-Al$\mathrm{_2}$O$\mathrm{_3}$

Bonny Dongre·Jesús Carrete·Natalio Mingo·Georg K H Madsen
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Abstract

The thermal conductivities ($\kappa$) of bulk and thin-film $\alpha$-Al$_2$O$_3$ are calculated from first principles using both the local density approximation (LDA), and the generalized gradient approximation (GGA) to exchange and correlation. The room temperature single crystal LDA value $\sim39~$W/m$~$K agrees well with the experimental values $\sim35-39~$W/m$~$K, whereas the GGA values are much smaller $\sim$26$~$W/m$~$K. Throughout the temperature range, LDA is found to slightly overestimate $\kappa$ whereas GGA strongly underestimates it. We calculate the $\kappa$ of crystalline $\alpha$-Al$\mathrm{_2}$O$\mathrm{_3}$ thin films and observe a maximum of 79$\%$ reduction for $10~$nm thickness.

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Bonny Dongre, Jesús Carrete, Natalio Mingo, Georg K H Madsen. 2018-06-22. Ab initio lattice thermal conductivity of bulk and thin-film $\alpha$-Al$\mathrm{_2}$O$\mathrm{_3}$. https://doi.org/10.1557/mrc.2018.161

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