We have studied the effects of phonon-boundary scattering on the thermal transport in topological Kondo insulator, SmB6. The studies have been performed by using the 3ω method in the temperature range 300K - 3K. We show that the observed thermal conductivity of micro-size SmB6 is of the order of magnitude smaller than for a bulk single-crystal. Using the Callaway model we analyzed the low-temperature lattice thermal conductivity of the micro crystal and show that phonon scattering by sample boundaries plays a major role in the thermal resistance in this topological material. In addition, we show that the temperature dependence of the lattice thermal conductivity shows a double peak structure that suggests complex phonon-phonon or phonon-defects interactions in SmB6. These findings provide guidance for the understanding of the thermal transport of advanced materials and devices at a micro-scale.
@article{arxiv.2208.01145,
title = {Boundary scattering in micro-size crystal of topological Kondo insulator SmB$_6$},
author = {Narayan Poudel and Daniel J. Murray and Jason R. Jeffries and Krzysztof Gofryk},
journal= {arXiv preprint arXiv:2208.01145},
year = {2022}
}