Abstract Scope |
Zintls, with their vast range of structural patterns and excellent thermoelectric performance, stand out as an intriguing subject area for the study of transport anisotropy. In the present study, we use a combination of theory and experiment to investigate the anisotropic transport properties of Ca5In2Sb6, which is characterized by anionic sub-structures resembling infinite 1D chains of corner-linked MSb4 tetrahedra. Ca5In2Sb6 single crystals grown from an Sb-rich molten flux were found to form long, needle-like crystals oriented parallel to the polyanionic chains. Due to the small cross-section of the crystals, characterization of transport properties in the direction perpendicular to the chains is challenging. For this purpose, micro-ribbons were extracted from single crystals using focused ion beam milling, and laser photolithography was used to deposit contacts to measure electrical resistivity. The resistivity parallel to the growth direction was found to be nearly 20 times higher than the perpendicular direction, confirming predictions. |