Search results for "Thermoelectric effect"
showing 10 items of 147 documents
Investigation of the Thermoelectric Properties of the Series TiCo1-xNixSnxSb1-x
2010
The effect of the simultaneous substitution of cobalt by nickel and antimony by tin in the solid solution TiCo1–xNixSnxSb1–x was systematically investigated. The number of valence electrons does not change by this substitution and therefore the resistivity stays semimetallic or semiconducting. The series were synthesized by arcmelting and the thermoelectric properties were determined. It was found out that the substitution of cobalt and antimony by nickel and tin reduces the thermal conductivity to 2 W·m–1·K–1 at 400 K. The reduction is caused by titanium rich prolate micro structures that were found by energy dispersive X-ray spectroscopy investigations. The Seebeck coefficient and the res…
Very large thermophase in ferromagnetic josephson junctions
2014
Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).
Length Scale of the Spin Seebeck Effect
2015
We investigate the origin of the spin Seebeck effect in yttrium iron garnet (YIG) samples for film thicknesses from 20 nm to 50 μm at room temperature and 50 K. Our results reveal a characteristic increase of the longitudinal spin Seebeck effect amplitude with the thickness of the insulating ferrimagnetic YIG, which levels off at a critical thickness that increases with decreasing temperature. The observed behavior cannot be explained as an interface effect or by variations of the material parameters. Comparison to numerical simulations of thermal magnonic spin currents yields qualitative agreement for the thickness dependence resulting from the finite magnon propagation length. This allow…
Thermoelectric effects on electrically conducting particles in liquid metal
2015
International audience; The present paper deals with the thermoelectric effect on a solid electrically conducting particle immersed in a liquid metal under a temperature gradient. Superimposition of a static magnetic field induces thermoelectric magnetic (TEM) forces both in the solid and in the liquid. Considering a simple spherical particle, the electric current density and the corresponding forces can be calculated analytically. Two cases are considered according to the orientation of the magnetic field with respect to the temperature gradient. The corresponding flow fields around the particle are calculated in both cases. Grain motion is analyzed in the light of in-situ experiments perf…
Co-doping with boron and nitrogen impurities in T-carbon
2020
Previously, Ren et al. [Chem. Phys. 518, 69–73, 2019] reported the failure of Boron-Nitrogen (B-N) co-doping as inter B-N bond in T-carbon. In present work, a B-N atom pair is introduced in T-carbon as p-n co-dopant to substitute two carbon atoms in the same carbon tetrahedron and form an intra B-N bond. The stability of this doping system is verified from energy, lattice dynamic, and thermodynamic aspects. According to our B3PW calculations, B-N impurities in this situation can reduce the band gap of T-carbon from 2.95 eV to 2.55 eV, making this material to be a promising photocatalyst. Through the study of its transport properties, we can also conclude that B-N co-doping cannot improve th…
On the Phase Separation in n-Type Thermoelectric Half-Heusler Materials
2018
Half-Heusler compounds have been in focus as potential materials for thermoelectric energy conversion in the mid-temperature range, e.g., as in automotive or industrial waste heat recovery, for more than ten years now. Because of their mechanical and thermal stability, these compounds are advantageous for common thermoelectric materials such as Bi 2 Te 3 , SiGe, clathrates or filled skutterudites. A further advantage lies in the tunability of Heusler compounds, allowing one to avoid expensive and toxic elements. Half-Heusler compounds usually exhibit a high electrical conductivity σ , resulting in high power factors. The main drawback of half-Heusler compounds is their high lattice th…
Towards higher zT in early transition metal oxides: optimizing the charge carrier concentration of the WO3-x compounds
2018
Abstract Thermoelectric devices are believed to play an important role in the energy research for the next decades. Thanks to their low costs coupled with high stability and sustainability, metal oxides are very promising materials even if their efficiencies still need improvements to ensure a wide applicability. Slightly reduced early transition metal oxides show intrinsic defects in the crystal structure which guarantee very low values of the thermal conductivity. The challenge to fulfil the “phonon-glass electron-crystal” concept is to decouple the optimization of the electronic properties from the thermal transport properties. In this contribution we report the optimization of the charg…
Giant Spin Seebeck Effect through an Interface Organic Semiconductor
2019
Interfacing an organic semiconductor C60 with a non-magnetic metallic thin film (Cu or Pt) has created a novel heterostructure that is ferromagnetic at ambient temperature, while its interface with a magnetic metal (Fe or Co) can tune the anisotropic magnetic surface property of the material. Here, we demonstrate that sandwiching C60 in between a magnetic insulator (Y3Fe5O12: YIG) and a non-magnetic, strong spin-orbit metal (Pt) promotes highly efficient spin current transport via the thermally driven spin Seebeck effect (SSE). Experiments and first principles calculations consistently show that the presence of C60 reduces significantly the conductivity mismatch between YIG and Pt and the s…
Influence of Nb-doping on the local structure and thermoelectric properties of transparent TiO2:Nb thin films
2020
The experiment at HASYLAB/DESY was performed within the project I-20180036 EC. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. Filipe Correia is grateful to the Fundação para a Ciência e Tecnologia (FCT, Portugal) for the Ph.D. Grant SFRH/BD/111720/2015 . Joana Ribeiro is grateful to the Project WinPSC - POCI-01-0247-FEDER-017796, for the research grant, co-funded by the European Regional Development Fund (ERDF) , through the Operational Programme for Competitiveness and Internationalisation (COMPETE 2020), under the PORTUGAL 2020 Partnership Agreement…
The local atomic structure and thermoelectric properties of Ir-doped ZnO: hybrid DFT calculations and XAS experiments
2021
We greatly acknowledge the financial support via the ERAF Project No. 1.1.1.1/18/A/073. Calculations have been performed under the Project HPC-EUROPA3 (INFRAIA-2016-1-730897), with the support of the EC Research Innovation Action under the H2020 Programme. A. C. gratefully acknowledges the technical support received from KTH-PDC. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2