Controlling heat flow in a solid by switching crystal structure dimensionality

"could reversibly switch between 3D and 2D crystal structure dimensionalities of (Pb0.5Sn0.5)Se polycrystals by heating and cooling... In heated state, material assumed 3D crystal structure with metallic electronic structure, which resulted in high electronic, lattice thermal conductivity. When cooled, changed to 2D crystal structure with semiconducting electronic structure and reduced κ. At 373 K (100°C), κ for 3D phase observed 3.6 times higher than for 2D phase"

Related: Heat flow shown to be more efficient when temperature is oscillating than when static

https://phys.org/news/2022-04-shown-efficient-temperature-oscillating-static.html