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

Bonny Dongre; Jesús Carrete; Natalio Mingo; Georg K H Madsen

doi:10.1557/mrc.2018.161

paper

Ab initio lattice thermal conductivity of bulk and thin-film $α$ -Al $_{2}$ O $_{3}$

arXiv:1806.08557 · doi:10.1557/mrc.2018.161

Abstract

The thermal conductivities ( $κ$ ) of bulk and thin-film $α$ -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 $\sim 39$ W/mK agrees well with the experimental values $\sim 35 - 39$ W/mK, whereas the GGA values are much smaller $\sim$ 26W/mK. Throughout the temperature range, LDA is found to slightly overestimate $κ$ whereas GGA strongly underestimates it. We calculate the $κ$ of crystalline $α$ -Al $_{2}$ O $_{3}$ thin films and observe a maximum of 79 $%$ reduction for $10$ nm thickness.

10 pages, 4 figures, 1 table

Ab initio lattice thermal conductivity of bulk and thin-film α-Al2​O3​

Abstract

Ab initio lattice thermal conductivity of bulk and thin-film $α$ -Al $_{2}$ O $_{3}$