Lattice thermal conductivity of TiS2 , ZrS2 , and HfS2 : Periodic trends studied by dispersion-corrected hybrid density functional methods

Abstract

The lattice thermal conductivity of layered group 4 disulfides ${\mathrm{TiS}}_{2}$, ${\mathrm{ZrS}}_{2}$, and ${\mathrm{HfS}}_{2}$ has been studied using dispersion-corrected hybrid density functional methods. Results obtained using both relaxation time approximation (RTA) and full solution of linearized Boltzmann transport equation have been compared and rigorously analyzed. The periodic trends of lattice thermal conductivity and its components are investigated in detail. The in-plane RTA lattice thermal conductivities of ${\mathrm{TiS}}_{2}$, ${\mathrm{ZrS}}_{2}$, and ${\mathrm{HfS}}_{2}$ at 300 K are 6.1, 8.5, and $11.7\phantom{\rule{4pt}{0ex}}\mathrm{W}\phantom{\rule{4pt}{0ex}}{\mathrm{m}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$, respectively. In the cross-plane direction, where the metal sulfide layers are kept together by weak van der Waals interactions, the RTA lattice thermal conductivities of ${\mathrm{TiS}}_{2}$, ${\mathrm{ZrS}}_{2}$, and ${\mathrm{HfS}}_{2}$ at 300 K are 1.4, 1.4, and $2.0\phantom{\rule{4pt}{0ex}}\mathrm{W}\phantom{\rule{4pt}{0ex}}{\mathrm{m}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$, respectively.