Influence of stacking disorder on cross-plane thermal transport properties in TMPS3 (TM = Mn, Ni, Fe).

We investigated the thermal transport properties of magnetic van der Waals materials, TMPS₃ (TM = Mn, Ni, and Fe), using the time-domain thermoreflectance technique. We determined the cross-plane thermal conductivity, which turns out to be relatively low, i.e., about 1 W m⁻¹ K⁻¹ for all TMPS₃ investigated. When compared with previous results of graphite and transition metal dichalcogenides (TMDs), thermal conductivity becomes smaller as it goes from graphite to TMDs to TMPS₃, and the difference is larger at low temperature, e.g., around 50 K. From the Callaway model analysis, we could attribute the large thermal conductivity reduction for TMPS₃, particularly at low temperature, to the phonon scattering from the boundary. We actually confirmed the existence of the large population of the stacking faults with the cross-sectional transmission electron microscopy image of MnPS₃. This suggests that intrinsic or extrinsic stacking faults formed in van der Waals materials and their heterostructures can play an important role in reducing the cross-plane thermal conductivity as a source of the boundary scattering. [ABSTRACT FROM AUTHOR]