Synthesis of Cage-structured Compounds for Thermoelectricity

The ability to directly convert between heat and electricity makes thermoelectric materials appealing. The main issue is that the physical parameters used to determine thermoelectric performance work against one another. For achieving the optimum performance, hindering lattice vibration by forming cage structures in which heavy atoms can rattle is a plausible way. Millimeter-sized single crystals of AB₂Zn₂₀ compounds (A and B are transition metals or rare earth elements and reside within Zn cages) have been successfully grown with the Zn self-flux technique, including previously unknown 5th- and 6th-period transition metal-containing phases. Structural studies have been performed with x-ray diffraction and Raman spectroscopy, followed by magnetization measurements and thermoelectric characterizations.