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Skutterudites are one of the most efficient materials for use in thermoelectric applications. From an industrial point of view, along with the high efficiency of thermoelectric materials, it becomes actual to develop a rapid, scalable, and energy-efficient fabrication technique. In this regard, mechanochemical synthesis has gained significant attention as a promising approach. In this work, we demonstrate the applicability and the potential of mechanochemical synthesis for the preparation of p-type skutterudites using Yb0.75Ce0.25Fe3.5Co0.5Sb12 composition as an example. In fact, the time spent on a full cycle of synthesis of bulk samples is less than 10 h, and the highest figure of merit value was 0.62, which is comparable to the values for similar compositions from previously works, where the time for synthesis is tens of times longer. [ABSTRACT FROM AUTHOR]

Oxides are of interest for thermoelectrics due to their high thermal stability, chemical inertness, low cost, and eco‐friendly constituting elements. Here, adopting a unique synthesis route via chemical co‐precipitation at strongly alkaline conditions, one of the highest thermoelectric performances for ZnO ceramics (PFmax=$PF_{\text{max}} =$ 21.5 µW cm−1 K−2 and zTmax=$zT_{\text{max}} =$ 0.5 at 1100 K in Zn0.96Al0.04O${\rm Zn}_{0.96} {\rm Al}_{0.04}{\rm O}$) is achieved. These results are linked to a distinct modification of the electronic structure: charge carriers become trapped at the edge of the conduction band due to Anderson localization, evidenced by an anomalously low carrier mobility, and characteristic temperature and doping dependencies of charge transport. The bi‐dimensional optimization of doping and carrier localization enable a simultaneous improvement of the Seebeck coefficient and electrical conductivity, opening a novel pathway to advance ZnO thermoelectrics. [ABSTRACT FROM AUTHOR]

Halide perovskites possess ultra-low thermal conductivity and show high potential for thermoelectric devices. The chemical properties and molecular structure of halide perovskite materials are not completely stable under ambient conditions, which hinders their use in thermoelectric generators. Changes in the properties of bulk halide perovskite thermoelectrics are accompanied by partial phase transitions and surface oxidation processes. In this paper, we conducted a comprehensive study of the transport and structural properties of CsSnI3, which were pristine by vacuum melting followed by spark plasma sintering. The research results on the electrical transport of these materials revealed that exposure to an inert atmosphere does not deteriorate stability and the properties of the materials remain unchanged. However, prolonged exposure to air leads to a significant degradation of the electrical transport properties. Contrary to thin-film samples, the shift to the double perovskite structure from the perovskite one is limited to a specific surface layer. This change significantly influences the electrical transport of the material while maintaining the essential properties of both perovskite types. [ABSTRACT FROM AUTHOR]

In this work, Bi1-xPbxCu1-x SeO (x = 0, 0.02, 0.06, and 0.08) compounds were synthesized by a solid state reaction followed by spark plasma sintering. The effect of simultaneous Bi to Pb substitution and Cu vacancy introduction on thermoelectric properties was investigated systematically. The power factor was significantly enhanced, contributing to the increase in the zT value. As a result, the zTmax of 0.75 at 773 K was obtained for the Bi0.94Pb0.06Cu0.94SeO sample. To reveal the factors constraining the zTmax of Bi1-xPbxCuSeO-based oxyselenides, a further careful analysis of literature data was performed. We highlighted that for Pb-doped oxyselenides, the power factor is almost independent of the synthesis technique, while the lattice thermal conductivity is the main property determining zTmax and is highly affected by the synthesis method. [ABSTRACT FROM AUTHOR]

In-filled skutterudites InxCo4Sb12 have attracted much attention due to their relatively high thermoelectric performance, which, in turn, is attributed to the In atoms acting as rattlers in the skutterudite voids and to the formation of InSb precipitates when the In solubility limit is exceeded (0.22 ≤ xmax ≤ 0.27). In this work, to suppress the formation of the unwanted CoSb2 phase and favor the formation of InSb precipitates, the following composition of In1Co4Sb12+δ with In concentration much higher than the solubility limit and Sb overstoichiometry was used. Three sets of bulk specimens with a nominal composition of In1Co4Sb12+δ were synthesized by conventional induction melting followed by (1) ball milling (BM) and spark plasma sintering (SPS), (2) BM and SPS followed by high-temperature annealing, and (3) melt spinning and SPS. The utilization of different sample preparation methods and processing conditions leads to samples with different microstructures and InSb precipitates of different shapes, sizes, and distributions. Thus, for all samples with the same nominal composition of In1Co4Sb12+δ, zTmax varies from 0.7 to 1.3 at 673 K only because of microstructural modification. A maximum zT value of around 1.3 was obtained at 673 K for the sample prepared using induction melting followed by annealing, melt spinning, and SPS. [ABSTRACT FROM AUTHOR]

First-principles calculations of the stability, electronic, and magnetic properties of full-Heusler compound V2FeSi and Fe2VSi in regular ( L 2 1 ) and inverse ( X A ) structures have been performed using density functional theory within an SCAN meta-GGA functional. It is found that the X A crystal lattice is energetically more favorable for V2FeSi, while Fe2VSi forms the L 2 1 structure. In both cases, the electronic structure of the energetically stable modifications corresponds to half-metallic ferrimagnets. Magnetic properties of energetically favorable structures obey the Slater–Pauling rule. All considered properties of the studied structures are explained within the crystal orbital Hamilton population analysis. [ABSTRACT FROM AUTHOR]

Structural, electronic, and magnetic properties of Mn2Co1-xVxZ (Z = Ga, Al, x = 0, 0.25, 0.5, 0.75, 1) Heusler alloys were theoretically investigated for the case of L21 (space group Fm 3 ¯ m), L21b (L21 structure with partial disordering between Co and Mn atoms) and XA (space group F 4 ¯ 3m) structures. It was found that the XA structure is more stable at low V concentrations, while the L21 structure is energetically favorable at high V concentrations. A transition from L21 to XA ordering occurs near x = 0.5, which qualitatively agrees with the experimental results. Comparison of the energies of the L21b and XA structures leads to the fact that the phase transition between these structures occurs at x = 0.25, which is in excellent agreement with the experimental data. The lattice parameters linearly change as x grows. For the L21 structure, a slight decrease in the lattice constant a was observed, while for the XA structure, an increase in a was found. The experimentally observed nonlinear behavior of the lattice parameters with a change in the V content is most likely a manifestation of the presence of a mixture of phases. Almost complete compensation of the magnetic moment was achieved for the Mn2Co1-xVxZ alloy (Z = Ga, Al) at x = 0.5 for XA ordering. In the case of the L21 ordering, it is necessary to consider a partial disorder of atoms in the Mn and Co sublattices in order to achieve compensation of the magnetic moment. [ABSTRACT FROM AUTHOR]

In this work, Bi 1- x Pb x Cu 1- x SeO ( x = 0, 0.02, 0.06, and 0.08) compounds were synthesized by a solid state reaction followed by spark plasma sintering. The effect of simultaneous Bi to Pb substitution and Cu vacancy introduction on thermoelectric properties was investigated systematically. The power factor was significantly enhanced, contributing to the increase in the zT value. As a result, the zT max of 0.75 at 773 K was obtained for the Bi 0.94 Pb 0.06 Cu 0.94 SeO sample. To reveal the factors constraining the zT max of Bi 1- x Pb x CuSeO-based oxyselenides, a further careful analysis of literature data was performed. We highlighted that for Pb-doped oxyselenides, the power factor is almost independent of the synthesis technique, while the lattice thermal conductivity is the main property determining zT max and is highly affected by the synthesis method.