A5064897069- Advanced Thermoelectric Materials and Devices
- Semiconductor materials and interfaces
- Thermal properties of materials
- Thermodynamic and Structural Properties of Metals and Alloys
- Thermal Expansion and Ionic Conductivity
- Intermetallics and Advanced Alloy Properties
- Heusler alloys: electronic and magnetic properties
- Thermal Radiation and Cooling Technologies
- Advanced Thermodynamics and Statistical Mechanics
- Chalcogenide Semiconductor Thin Films
- Surface and Thin Film Phenomena
- Rare-earth and actinide compounds
- Phase-change materials and chalcogenides
- Heat Transfer and Optimization
- Metallurgical and Alloy Processes
- Advanced Semiconductor Detectors and Materials
- Electronic Packaging and Soldering Technologies
- Aluminum Alloys Composites Properties
- Topological Materials and Phenomena
- Superconductivity in MgB2 and Alloys
- Aluminum Alloy Microstructure Properties
- Spacecraft and Cryogenic Technologies
- Thermography and Photoacoustic Techniques
- Machine Learning in Materials Science
- Optical properties and cooling technologies in crystalline materials
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2016-2025
Justus-Liebig-Universität Gießen
2015-2024
Linde (Germany)
2015-2020
Institute of Materials Research of the Slovak Academy of Sciences
2009-2019
LVR-Klinik Köln
2018-2019
Geospace Research (United States)
2013
KTH Royal Institute of Technology
2006-2008
Tongji University
2006
Martin Luther University Halle-Wittenberg
2002
University of Tübingen
2000
Abstract The high concentration of grain boundaries provided by nanostructuring is expected to lower the thermal conductivity thermoelectric materials, which favors an increase in their figure‐of‐merit, ZT . A novel chemical alloying method has been used for synthesis nanoengineered‐skutterudite CoSb 3 powders were annealed different durations obtain a set samples with particle sizes. then compacted into pellets uniaxial pressing under various conditions and characterization. transport...
Abstract The lattice dynamics in the IV–VI compounds GeTe, SnTe and PbTe were studied by 125 Te 119 Sn nuclear inelastic scattering obtained partial density of phonon states compared with published theoretical calculations. phase purity structure characterized high energy X‐ray diffraction. effect atomic arrangement, rhombohedral for GeTe cubic PbTe, is visible states. Vibrational properties are found to be good agreement available calculated data softer character NaCl‐type structures...
The Seebeck coefficient is one of the key quantities thermoelectric materials and routinely measured in various laboratories. There are, however, several ways to calculate from raw measurement data. We compare these different extract coefficient, evaluate accuracy results, show methods increase this accuracy. furthermore point out experimental data analysis parameters that can be used trustworthiness obtained result. shown find minimize errors therefore reliability material properties.
Partially filled CoSb3 skutterudite compounds are emerging materials for thermoelectric energy conversion at high temperature. CaxCo4Sb12 with different Ca contents has been prepared by the conventional metallurgical route. The temperature dependences of electrical resistivity, Seebeck coefficient, and thermal conductivity have measured on these in 300–800 K range. These measurements identified as being a true n-type filler atom offer, this family skutterudite, several valuable insights into...
Bismuth telluride (Bi2Te3)-based solid solutions are state-of-the-art thermoelectric (TE) materials for cooling applications at room temperature with a high figure of merit ZT. Nanostructured TE bismuth thick films have been fabricated by electrodeposition from solution containing nitrate and tellurium dioxide in 1 M nitric acid onto gold-sputtered aluminum substrates. A conventional three-electrode cell was used platinum sheet as the counter electrode saturated calomel (SCE) reference...
Magnesium silicide based solid solutions are highly attractive materials for thermoelectric energy harvesting due to their abundance and excellent properties. Identification testing of suitable contacts is – besides material optimization the major challenge in development modules. We have applied Ni on doped Mg2Si samples using a simple one-step sintering technique. These were analyzed by combining microstructural analysis with spatially resolved temperature dependent contact resistance...
Exceptionally high thermoelectric figure of merit (zT>2), has been reported for (Ag1−ySbTe2)0.05(PbTe)0.95, which may involve the nanoscale microstructure. However, conflicting reports on same materials claim only zT 1 or less. Here we show that (Ag1−ySbTe2)0.05(PbTe)0.95 are multiphase scale millimeters despite appearing homogeneous by x-ray diffraction and routine electron microscopy. Using a scanning Seebeck microprobe, find significant variation coefficient (including both n-type...
Bismuth telluride is the state-of-the-art thermoelectric (TE) material for cooling applications with a figure of merit ∼1 at 300 K. There need development TE materials based on concept thick films miniaturized devices due to mechanical and manufacturing constraints thermoelement dimensions. We reported earlier method fabrication high-quality nanostructured bismuth thickness from 100 350 µm electrochemical deposition techniques. In this paper, annealing performed further improve performance...
Nanostructured skutterudite Co1−xNixSb3 has been synthesized by chemical alloying with Ni substitution for Co up to 27.5 at. %. High concentration of grain boundaries provided nanostructuring is expected lower the thermal conductivity thermoelectric materials and could thus increase their dimensionless figure-of-merit ZT. Material preparation comprises two key stages, coprecipitation precursor, processing produce skutterudite. By modeling chemistry metal ions in aqueous solution, optimum...
We have investigated the influence of nickel doping in a series n-type CoSb3 skutterudite materials partially filled with Ca. The electrical resistivity, thermopower, and thermal conductivity been measured 300–800 K temperature range on CayCo1−xNixSb12 compounds prepared by powder metallurgy route. chemical composition structure analyzed electron probe microanalyses x-ray diffraction, respectively. It was found that presence substantially decreases resistivity without any detrimental effect...
The properties of Te-doped Co(Sb1−yTey)3 and Te-Ni double-doped Co1−xNix(Sb1−yTey)3 nanostructured skutterudites were evaluated by means x-ray powder diffraction, transport measured on the synthesized samples have been compared with ab initio theoretical modeling. Theoretical optimal dopant contents according to maximum value power factor, calculating electronic from material band structure using semiclassical Boltzmann theory. chemical alloying Te substitution for Sb up 2.5at.% Ni Co...
In the present work, nano-ZrO2∕CoSb3 composites were fabricated by milling ZrO2 and CoSb3 powders hot pressing at different sintering temperatures. For prepared compacts, phase purity, microstructure, temperature-dependent thermoelectric properties characterized. The effect of nano-ZrO2 dispersion on composite electrical conductivity thermal is strictly clarified comparing transport nondispersed dispersed identical porosity, so that porosity parameters could be eliminated. insulating...
We have optimized the thermoelectric material Mg<sub>2</sub>Si<sub>0.8</sub>Sn<sub>0.2</sub> and analyzed electronic transport employing a single parabolic band model.
The influence of power factor enhancement on the superior thermoelectric (TE) performance Mg 2 (Si,Sn) is studied based a comparison with Si. Doped compounds compositions (Si 0.4 Sn 0.6 ) are synthesized and TE properties measured between room temperature 773 K. Carrier concentration hall mobilities at selected samples. Enhancement density‐of‐states effective mass comparable to Si indicate band convergence in solid solutions be cause enhancement. Microstructural analysis shows presence...
Abstract Decoupling charge and heat transport is essential for optimizing thermoelectric materials. Strategies to inhibit lattice-driven transport, however, also compromise carrier mobility, limiting the performance of most thermoelectrics, including Fe 2 VAl Heusler compounds. Here, we demonstrate an innovative approach, which bypasses this tradeoff: via liquid-phase sintering, incorporate archetypal topological insulator Bi 1− x Sb between V 0.95 Ta 0.1 Al grains. Structural investigations...
Nano ZrO2/CoSb3 composites with different ZrO2 contents were prepared using hot pressing. The phase purity, the microstructure and temperature-dependent transport parameters of investigated. dimensionless figure merit (ZT) 0.18 non-dispersed CoSb3 preponderates maximal value (0.17) pure reported in literature, which is attributed to sample having higher electrical conductivity due existence a small amount metallic Sb lower thermal fine-grained structure. Compared CoSb3, further improvement...