Experimental Realization of Heavily p-doped Half-Heusler CoVSn Compound

Abstract

Hypothetical half-Heusler (HH) ternary alloy of CoVSn has already been computationally investigated for possible spintronics and thermoelectric applications. We report the experimental realization of this compound and the characterizations of its thermoelectric properties. The material was synthesized by a solid-state reaction of the stoichiometric amounts of the elements via powder metallurgy (30 h mechanical milling and annealing at 900 °C for 20 h) and spark plasma sintering (SPS). The temperature-dependent ternary thermodynamic phase diagram of Co-V-Sn was further calculated. The phase diagram and detailed analysis of the synthesized material revealed the formation of the non-stoichiometry HH CoVSn, mixed with the binary intermetallic phases of SnV3, Co2Sn, and Co3V. The combination of X-ray diffraction, energy-dispersive X-ray spectroscopy, and thermoelectric transport properties confirmed the formation of a multi-phase compound. The analysis revealed the predicted thermoelectric features (zT = 0.53) of the highly doped CoVSn to be compromised by the formation of intermetallic phases (zT ≈ 0.007) during synthesis. The additional phases changed the properties from p- to overall n-type thermoelectric characteristics.

Assessment of Thermoelectric, Mechanical, and Microstructural Reinforcement Properties of Graphene-Mixed Heterostructures

“…Moreover, the microstructural analysis revealed multiphase microconstituents for the CoVSn-GNPs (e.g., CoVSn-1 wt % GNPsFigure ), similar to the pristine CoVSn sample, as discussed in ref Figure shows the elemental dispersion via X-ray mapping. It can be seen that the distributions of the main three elements, Co, V, and Sn, are not uniform, which confirms the presence of a multiphase microstructure.…”

“…The synthesis of the CoVSn compound has been reported, and its multiphase composition and microstructure were discussed in an earlier work by the authors (Figures S1 and S2). Here, the impacts of graphene nanoplate (GNP) reinforcement on the CoVSn microstructure and its properties are studied.…”

“…In the following section, we report a case study on CoVSn and study the effect of graphene on the thermoelectric, microstructure, and mechanical properties of the nanocomposite structure. The CoVSn composition was studied in its pristine phase and presented in a prior publication . Here, the heterogeneous composition is evaluated through reinforcement with graphene nanoplates.…”

Thermal Management Systems and Waste Heat Recycling by Thermoelectric Generators—An Overview

“…The efficiency of thermoelectric generators is very much dependent on the conversion efficiency of the constituent thermoelectric (TE) compounds [25][26][27][28][29]. Therefore, the introduction of advanced thermoelectric materials is crucial in increasing the waste heatelectricity conversion rate.…”

Applications of Thermoelectric Generators To Improve Catalytic-Assisted Hydrogen Production Efficiency: Future Directions

“…In this approach, thermoelectric generators (TEGs) have shown promising capabilities in recovering the low-grade waste energy. − This technology is an effective method employed to take full advantage of using wasted thermal energy to improve the efficiency of clean energy sources, such as solar and geothermal. Furthermore, TEGs offer the benefit of simple and durable design with no moving parts and noise and are easy to operate with zero emissions. − In addition to the recent advances in the development of TE materials − as the main recipe for manufacturing better TEGs, several applications have been proposed and designed to commercialize TEGs with enhanced efficiencies for energy-intensive industrial operations (Figure ). Figure a presents a setup to evaluate the performance of TEGs on the energy fluxes in a diesel engine, providing modifications in the energy flux distribution of the engine and improving its efficiency through a reduction in the heat loss by as much as 32% due to the incorporation of TEGs …”