Measuring heat conduction along all three axes of HfTe₅
Thermal conductivity along the a, b and c axes followed a ratio of about 28:1:8, with the weakest conduction across the layers.
Tianli Feng and colleagues used time-domain thermoreflectance to measure HfTe₅ single crystals along all three axes. The conductivity was about 11.3 W/(m·K) along the chains, 0.41 across the layers and 3.2 along the remaining in-plane axis.
First-principles calculations agreed with the measurements, providing an independent check on this large directional difference. SUSTech coauthors included Peipei Wang and Liyuan Zhang. The paper appeared online in December 2019 and in the journal’s 2020 volume.