Abstract
<jats:p>Lamellar InSb-Mg3Sb2 eutectic composites prepared via Bridgman directional solidification were investigated for their anisotropic thermoelectric performance. Electrical conductivity measured parallel (σ║) and perpendicular (σ┴) to the lamellae shows pronounced anisotropy, with higher than across 100-750 K and an anisotropy ratio increasing from ~6.7 to ~10.7. Thermal conductivity decreases with temperature, with a thermal anisotropy ratio decreasing from ~1.7 to ~1.1, indicating more isotropic phonon transport at elevated temperatures. The contrasting trends of electrical and thermal transport highlight the dominant role of phonons in heat conduction and structural control of charge transport. These findings demonstrate that the lamellar architecture critically governs directional thermoelectric properties, offering strategies for optimizing thermoelectric composites.</jats:p>