Impact of Lu-Substitution in YbLuZnSb: Thermoelectric Properties and Oxidation Studies.

YbZnSb is one of the newest additions to the high-performance YbMSb (M = Mn, Mg, and Zn) family of p-type high-temperature thermoelectric materials and shows promise for forming passivating oxide coatings. Work on the oxidation of rare earth (RE)-substituted YbREMnSb single crystals suggested that substituting late RE elements may form more stable passivation oxide coatings. YbLuZnSb ( = 0.

YTe: A New n-Type Thermoelectric Material.

Rare-earth chalcogenides ( = La, Pr, Nd, = S, Se, and Te) have been extensively studied as high-temperature thermoelectric (TE) materials owing to their low lattice thermal conductivity (κ) and tunable electron carrier concentration cation vacancies. In this work, we introduce YTe, a rare-earth chalcogenide with a rocksalt-like vacancy-ordered structure, as a promising n-type TE material. We computationally evaluate the transport properties, optimized TE performance, and doping characteristics of YTe.

Unlocking the thermoelectric potential of the CaAlSb structure type.

YbMnSb and YbMgSb are among the best p-type high-temperature (>1200 K) thermoelectric materials, yet other compounds of this CaAlSb structure type have not matched their stability and efficiency. First-principles computations show that the features in the electronic structures that have been identified to lead to high thermoelectric performances are present in YbZnSb, which has been presumed to be a poor thermoelectric material. We show that the previously reported low power factor of YbZnSb is not intrinsic and is due to the presence of a YbZnSb impurity uniquely present in the Zn system.

Discovery of multivalley Fermi surface responsible for the high thermoelectric performance in YbMnSb and YbMgSb.

The Zintl phases, Yb Sb ( = Mn, Mg, Al, Zn), are now some of the highest thermoelectric efficiency p-type materials with stability above 873 K. YbMnSb gained prominence as the first p-type thermoelectric material to double the efficiency of SiGe alloy, the heritage material in radioisotope thermoelectric generators used to power NASA's deep space exploration. This study investigates the solid solution of YbMg Al Sb (0 ≤ ≤ 1), which enables a full mapping of the metal-to-semiconductor transition.

Synthesis and characterization of vacancy-doped neodymium telluride for thermoelectric applications.

Thermoelectric materials exhibit a voltage under an applied thermal gradient and are the heart of radioisotope thermoelectric generators (RTGs), which are the main power system for space missions such as I, II, and the Mars rover. However, materials currently in use enable only modest thermal-to-electrical conversion efficiencies near 6.5% at the system level, warranting the development of material systems with improved thermoelectric performance.

Thermoelectric Properties of Scandium Sesquitelluride.

Rare-earth (RE) tellurides have been studied extensively for use in high-temperature thermoelectric applications. Specifically, lanthanum and praseodymium-based compounds with the Th₃P₄ structure type have demonstrated dimensionless thermoelectric figures of merit () up to 1.7 at 1200 K.

Seebeck and Figure of Merit Enhancement by Rare Earth Doping in YbREZnSb (x = 0.5).

YbZnSb has been of interest for its intermediate valency and possible Kondo designation. It is one of the few transition metal compounds of the CaAlSb structure type that show metallic behavior. While the solid solution of YbMnZnSb shows an improvement in the high temperature figure of merit of about 10% over YbMnSb, there has been no investigation of optimization of the Zn containing phase.

Mechanochemical Synthesis and High Temperature Thermoelectric Properties of Calcium-Doped Lanthanum Telluride LaCaTe.

The thermoelectric properties from 300 - 1275 K of calcium-doped LaTe are reported. LaTe is a high temperature n-type thermoelectric material with a previously reported zT ~ 1.1 at 1273 K and x = 0.

Nanostructured materials for thermoelectric applications.

Recent studies indicate that nanostructuring can be an effective method for increasing the dimensionless thermoelectric figure of merit (ZT) in materials. Most of the enhancement in ZT can be attributed to large reductions in the lattice thermal conductivity due to increased phonon scattering at interfaces. Although significant gains have been reported, much higher ZTs in practical, cost-effective and environmentally benign materials are needed in order for thermoelectrics to become effective for large-scale, wide-spread power and thermal management applications.