Heat conduction differs twelvefold between two axes of ZrTe₅
At room temperature, thermal conductivity along the interlayer b axis was about 0.33 W/(m·K), far below its value along the a axis.
Jie Zhu and colleagues used time-domain thermoreflectance to follow how ZrTe₅ cooled after a short heating pulse. The measurements resolved heat flow along different crystal axes. Liyuan Zhang co-authored the study.
At room temperature the crystal conducted heat only about one twelfth as efficiently along the interlayer b axis as along the a axis. The contrast quantifies how strongly the direction of heat flow matters in this layered solid.