# Thermal conductivity of the Kondo semiconductor CeRu$_4$Sn$_6$

## TL;DR

This study measures the thermal conductivity of CeRu$_4$Sn$_6$ single crystals across a broad temperature range, revealing phonon-dominated heat transport with isotropic behavior and electron scattering effects at low temperatures.

## Contribution

First comprehensive thermal conductivity measurements of CeRu$_4$Sn$_6$ single crystals, showing phonon dominance and isotropy, with analysis using a Callaway model.

## Key findings

- Thermal conductivity is phonon-dominated and isotropic.
- At low temperatures, $ppa \u2208 T^2$, indicating electron-phonon scattering.
- Callaway model fits the data well across all temperatures.

## Abstract

We report measurements of the thermal conductivity $\kappa$ on single crystalline CeRu$_4$Sn$_6$ in the temperature range between 80mK and 80K, along the main crystallographic directions. $\kappa$ is phonon-dominated in the whole temperature range and is found to be essentially isotropic. At low temperatures the data are well approximated by $\kappa \propto T^2$, which is attributed to a predominant scattering of phonons on electrons. We describe the data with a Callaway fit in the whole temperature range giving good agreement at low and high temperatures.