Thermoelectric Properties of Scandium Sesquitelluride

Abstract

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 (zT) up to 1.7 at 1200 K. Scandium, while not part of the lanthanide series, is considered a RE element due to its chemical similarity. However, little is known about the thermoelectric properties of the tellurides of scandium. Here, we synthesized scandium sesquitelluride (Sc2Te3) using a mechanochemical approach and formed sintered compacts through spark plasma sintering (SPS). Temperature-dependent thermoelectric properties were measured from 300–1100 K. Sc2Te3 exhibited a peak zT = 0.3 over the broad range of 500–750 K due to an appreciable power factor and low-lattice thermal conductivity in the mid-temperature range.

The study of the Kinetic Characteristics of Sorption of Scandium of Ion Exchanger Purolite MTS9580 from Return Circulating Solutions of Underground Leaching of Uranium Ores

“…It should be noted that ion-exchange resins swell (2) upon contact with aqueous solutions, as a result of which the pore sizes of ion exchangers in a swollen state can radically differ from the pores of ion exchangers in dry form, due to this circumstance, the data presented are only comparative.…”

“…Scandium is a precious and rare metal due to the high cost of scandium and the complex metallurgical processes of its isolation and purification. Scandium is used in high-strength aluminum alloys, solid oxide fuel cells, electronics and in laser technology and magnets [1,2,3]. A mixture containing scandium oxide in combination with an Al-CoCrFeNi alloy was investigated, which led to the discovery of a promising nanodiamond composite [4].…”

Special Issue: Advances in Zintl Phases

“…The authors provide a discussion of the complexity of this structure type and show with Pisarenko plots that further optimization of the zT is possible. The synthesis and thermoelectric properties of Sc 2 Te 3 are reported by Bux et al [8]. Motivated by the high zT ’s reported for RE 3−x Te 4 compounds, this work presents a low-temperature mechanochemical synthesis, high-temperature thermoelectric properties, and thermodynamic parameters such as elastic moduli, speed of sounds, thermal expansion, and Grüneisen parameter.…”

Y2Te3: A New n-type Thermoelectric Material

“…10 The orthorhombic crystal structure of Y 2 Te 3 (space group Fddd, Figure 1) can be understood as a rock-salt derived structure with ordered cation vacancies, which is isostructural with the orthorhombic polymorph of Sc 2 Te 3 . 25 The vacancy-ordered structures of Y 2 Te 3 and Sc 2 Te 3 are related to that of rhombohedral Sb 2 Te 3 , as evidenced by their phase transitions in phase-change memory alloys. 26 Specifically, the structural relationship can be understood as a gathering of the ordered vacancies in the orthorhombic structures to form a van der Waals gaps in the rhombohedral Sb 2 Te 3 structure, similar to the phase transition mechanism of Ge 2 Sb 2 Te 5 .…”

“…Inspired by this chemical space of materials, the valence-balanced Sc 2 Te 3 was synthesized and found to have k < 2 W/mK. 25 Due to the prevalence of rare-earth chalcogenide TE materials, it is, therefore, natural to ask if there are other potentially high-performing TE materials within this chemical space.…”