Additive fabrication and experimental validation of a lightweight thermoelectric generator.

We develop a thermoelectric generator based on catalytic combustion and operating in the low power range (up to 10 W). Considering the target of small-scale thermoelectric generators, the additive technique was chosen as an enabling technology to customize the different parts of the presented device. The generator consists of a hexagonal shaped combustion chamber coupled to commercial thermoelectric modules, water-cooled at the cold side.

Experimental and computational study of the role of defects and secondary phases on the thermoelectric properties of TiNiSn (0 ≤≤ 0.12) half Heusler compounds.

The half Heusler TiNiSn compound is a model system for understanding the relationship among structural, electronic, microstructural and thermoelectric properties. However, the role of defects that deviate from the ideal crystal structure is far from being fully described. In this work, TiNiSn alloys (= 0, 0.

Effects of Preparation Procedures and Porosity on Thermoelectric Bulk Samples of CuSnS (CTS).

The thermoelectric behavior and stability of CuSnS (CTS) has been investigated in relation to different preparations and sintering conditions, leading to different microstructures and porosities. The studied system is CTS in its cubic polymorph, produced in powder form via a bottom-up approach based on high-energy reactive milling. The as-milled powder was sintered in two batches with different synthesis conditions to produce bulk CTS samples: manual cold pressing followed by traditional sintering (TS), or open die pressing (ODP).

Topological Anderson Insulator in Cation-Disordered CuZnSnS.

We present the first candidate for the realization of a disorder-induced Topological Anderson Insulator in a real material system. High-energy reactive mechanical alloying produces a polymorph of CuZnSnS with high cation disorder. Density functional theory calculations show an inverted ordering of bands at the Brillouin zone center for this polymorph, which is in contrast to its ordered phase.

Physical Characterization of Sintered NiMnGa Ferromagnetic Shape Memory Alloy.

The present work focused on the microstructural, thermal, electrical, and damping characterization of NiMnGa samples produced through a powder pressing and a sintering process; the effect of sintering times and of the starting powder size were evaluated. Moreover, an observation of the evolution of martensitic transformation typical of NiMnGa ferromagnetic shape memory alloy was conducted in comparison with the cast material behavior and in correlation with the material densification. The optimum powder size and sintering time for the process, i.

Effect of the Order-Disorder Transition on the Seebeck Coefficient of Nanostructured Thermoelectric CuZnSnS.

Bulk samples of kesterite (CuZnSnS, CZTS) were produced by cold-pressing and sintering of CZTS powders obtained via reactive ball-milling. An increase in the Seebeck coefficient of more than 100 μV/K, almost doubling the expected value, is noticed around a temperature of 260 °C. As pointed out by thermal analyses, this is due to a second order transition of kesterite from an ordered I-4 to a disordered I-42m crystal structure.

Nanostructured Tetrahedrite Synthesis for Thermoelectric Applications.

Nowadays, a big challenge in the thermoelectric field is the identification of efficient thermoelectric materials but inexpensive, easy to synthesize, and comprised of Earth-abundant elements. On this basis, tetrahedrite mineral family (Cu(12−x)Tr(x)Sb₄S₁₃ where Tr = Cu, Mn, Fe, Co, Ni, Zn) seems to be an attractive p-Type Pb-free thermoelectric material, showing a relatively high conversion efficiency. In this work, a solvothermal synthesis method was developed for undoped tetrahedrite Cu₁₂Sb₄S₁₃ and the introduction of Zn and Ni as substituents of copper was also tested.

Study of the Performances of a Thermoelectric Generator Based on a Catalytic Meso-Scale H₂/C₃H₈ Fueled Combustor.

In this work the thermoelectric generator (TEG) based on catalytic combustion already developed in our lab has been further investigated and improved. The system made of two thermoelectric (TE) modules coupled with a catalytic combustor has been used in this work to obtain higher overall efficiency by adding hydrogen to the fuel mixture. Since implementation of hydrogen as a fuel has shown low and stable combustion temperature in literature, it is expected to achieve good overall efficiency of TEG.

Correlations between Structural and Electronic Properties in the Filled Skutterudite Smy(FexNi1-x)4Sb12.

A structural study of the filled skutterudite Smy(FexNi1-x)4Sb12 was performed by means of X-ray powder diffraction and μ-Raman spectroscopy with the aim to unveil the correlations between structural and electronic properties of this material and to favor the improvement of its thermoelectric performance. Samples were prepared by direct reaction of the elements at 1223 K, followed by quenching and subsequent sintering at 873 K; microstructure and composition of the obtained products were determined by SEM-EDS. The position of the boundary separating regions that obey hole- and electron-based conduction mechanisms was found by X-ray diffraction at x ≈ 0.