Advancing the Ca₁₄AlSb₁₁ Structure Type: Synthesis and Characterization of Yb₁₄CdSb₁₁ for Thermoelectric Applications

The ternary phase, Yb 14 CdSb 11 , has been synthesized by flux and polycrystalline methods. The crystal structure is determined via single‐crystal X‐ray diffraction, revealing that it crystallizes in the Ca 14 AlSb 11 structure type ( I 4 1 / acd space group with unit cell parameters of a = 16.5962(2) Å and c = 22.1346(5) Å, 90 K, Z = 8, R 1 = 2.65%, and wR 2 = 4.58%). The polycrystalline form of the compound is synthesized from a stoichiometric reaction of Yb 4 Sb 3 , CdSb, Yb, and Sb. The elemental composition is confirmed using scanning electron microscopy and energy‐dispersive spectroscopy, and phase purity is verified by powder X‐ray diffraction. Thermoelectric measurements, including resistivity, Seebeck coefficient, thermal conductivity, Hall carrier concentration, and Hall mobility, are conducted from 300 to 1273 K. Yb 14 CdSb 11 exhibits a peak zT = 0.90 at 1200 K. Carrier concentration and Hall mobility range from 6.99 × 10 20 –1.01 × 10 21 cm −3 and 4.45–9.35 × 10 −1 cm 2 V − 1 s − 1 , respectively. This carrier concentration is lower than that reported for the Zn or Mn analogs leading to a lower thermoelectric figure of merit at high temperatures. However, with appropriate doping, this phase should also be a promising p ‐type candidate for high‐temperature energy conversion applications.