Year: 2025
Type: article
Abstract: YbCuSb was synthesized via an improved quasi-solid-state synthesis method for this compound using either an open carbon crucible or a sealed stainless steel crucible. The former crucible led to a total fraction of secondary phases of 25% whereas the latter one led to less than 2% of secondary phases. Densification was performed by spark plasma sintering to reach relative density values larger than 94%. These densified YbCuSb samples are air- and water-stable at room temperature. Combined electronic transport measurements and ab initio electronic structure calculations led to the conclusion that YbCuSb is a semiconductor and can be classified as a Zintl compound. The present samples showed p -type conduction with large values of electronic mobility (78 cm 2 V –1 s –1 at 300 K) and a small density of states effective mass (0.4 m 0, with m 0 the bare electron mass). They also displayed small values of Seebeck coefficient (9–14 μV K –1 at 300 K) and power factor (0.04–0.07 mW m –1 K –2 at 300 K) due to too large hole concentrations (2.9–7.6 × 10 20 cm –3 ). The lattice thermal conductivity was small (λ L = 1.5 W m –1 K –1 ), as expected from the overall trend in the ACuSb series (A = Ca, Sr, Ba, Eu, and Yb) and from the heavy atomic mass of Yb. Nonetheless, the modest values of power factor led to small values of thermoelectric figure of merit: maximum ZT = 0.09 at 700 K.
Source: ACS Applied Energy Materials
Authors: E. Dirican, A. Moll, C. Barreteau, E. Alleno
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7081950035