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Magnetic field effects have been instrumental to unveil several exotic phenomena in two-dimensional (2D) materials. Here, we show that graphene exhibits self-similar transport once the material is nanostructured with a magnetic field in complex fashion. In specific, when magnetic barriers are arranged according to the Cantor set rules. In this study, the charge carriers are described as quantum relativistic particles through an effective low-energy Hamiltonian. The transmission, transport and thermoelectric properties are computed with the transfer matrix method, the Landauer–Büttiker formalism and the Cutler–Mott formula, respectively. Self-similarity is reflected in the conductance spectra and Seebeck coefficient for different structural parameters such as generation number, the intensity of the magnetic field, the height of the barrier and the total length of the system. Moreover, well-defined scaling rules, which described fairly good the scalability between self-similar patterns, are obtained. We also compare the self-similar patterns of magnetic complex structures with the corresponding ones to magnetic-electric complex structures, finding better scalability for the former. It is worth mentioning that as far as we have corroborated the breaking symmetry associated to the magnetic field is paramount for the self-similar transport. So, magnetic complex structures constitute an excellent option to corroborate the peculiar phenomenon of self-similar transport.

During the past two years, we have underlined the great potential of p-type oxychalcogenides, with parent compound BiCuSeO, for thermoelectric applications in the medium temperature range (400–650°C). These materials, which do not contain lead and are less expensive than Te containing materials, exhibit large thermoelectric figure of merit, exceeding 1 in a wide temperature range, mainly due to an intrinsically very low thermal conductivity. This paper summarizes the main chemical and crystallographic features of this system, as well as the thermoelectric properties. It also gives new directions to improve these properties, and discuss the potential of these materials for wide scale applications in thermoelectric conversion system in the medium temperature range.

A dedicated test stand was developed and built to characterize the efficiency, power output and open circuit voltage of various thermoelectric generators (TEGs) based on tellurides, heusler compounds and thermoelectric oxides. The test stand allows measurements of TEGs of sizes up to 4 cm × 4 cm at hot side temperatures up to 1150 K in different atmospheres. Special care was taken about the heat flux measurement by precise measurement of the temperature distribution within the reference block. In order to demonstrate the functionality of the test stand thermoelectric oxide modules (TOM) were built from n-type perovskite-type manganates and p-type cuprates. The modules were tested regarding their stability, maximum power output and efficiency at temperatures up to 1100 K. The TOMs withstand large temperature gradients and operated in ambient air yielding high power densities.

We have studied the structural, electronic, magnetic, thermoelectric and optical properties of the half-metal BaRuO₃ using the accurate full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). The generalized gradient approximation (GGA) was used to treat the exchange and correlation potential. The GGA$+U$ approximation was also used to enhance the description of the electronic structure after calculating theoretically the Coulomb repulsion ($U=7$eV). The ferromagnetic (FM) phase of BaRuO₃ is more stable. This result is in accordance with experimental and theoretical calculations. The calculated magnetic moments in BaRuO₃ were found to arise especially from the Ru-4d state electrons. We have obtained the semiconductor gap (0.9eV) in spin-up while in spin down, the metal character was dominant, and therefore BaRuO₃ has a half-metallic behavior. The thermoelectric efficiency was 0.12 at room temperature. Here we have considered only the electronic thermal conductivity, we have not included the lattice thermal conductivity. The relaxation time was assumed constant. The $\mathrm{\text{GGA}}+U$ approximation was also used to analyze the optical properties by determining the complex dielectric function from which are derived the other parameters.

Thermoelectric source has proven its efficaciousness as a clean and affordable alternative energy source. Thermoelectric generators are the ones which can produce electricity from heat. The concept of thermoelectricity, its production and its related concepts are reviewed in this paper. Peltier tile, a device used as a TEG, is used in various ways to produce electricity which are thoroughly reviewed in this paper. Thermoelectricity produces from these tiles proves to be a very good source of alternate energy. Despite technological revolutions, there are many places devoid of electricity due to various reasons. Thermoelectricity generation would prove to be a very clean and affordable alternative energy source in these areas. This paper reviews TEG how it generates a clean, affordable and easily accessible energy: electricity, without the need of transmission lines.