A5046970190- Advanced Thermoelectric Materials and Devices
- Advanced Thermodynamics and Statistical Mechanics
- Phase-change materials and chalcogenides
- Optical properties and cooling technologies in crystalline materials
- Intermetallics and Advanced Alloy Properties
- Thermal properties of materials
- Heusler alloys: electronic and magnetic properties
- Metal and Thin Film Mechanics
- Chalcogenide Semiconductor Thin Films
- Magnesium Alloys: Properties and Applications
- nanoparticles nucleation surface interactions
- Aluminum Alloys Composites Properties
- Advanced Materials Characterization Techniques
- MXene and MAX Phase Materials
- Aluminum Alloy Microstructure Properties
- Ionic liquids properties and applications
- Advanced Semiconductor Detectors and Materials
- Material Science and Thermodynamics
- Thermography and Photoacoustic Techniques
- Rare-earth and actinide compounds
- Electron and X-Ray Spectroscopy Techniques
- Quantum Dots Synthesis And Properties
- Thermodynamic and Structural Properties of Metals and Alloys
- Phase Equilibria and Thermodynamics
- Machine Learning in Materials Science
Max-Planck-Institut für Nachhaltige Materialien
2016-2024
Max Planck Society
2016-2021
Abstract Dislocations play an important role in thermal transport by scattering phonons. Nevertheless, for materials with intrinsically low conductivity, such as thermoelectrics, classical models require exceedingly high numbers of dislocations (>10 12 cm –2 ) to further impede transport. In this work, a significant reduction conductivity Na 0.025 Eu 0.03 Pb 0.945 Te is demonstrated at moderate dislocation density 1 × 10 . Further characteristics dislocations, including their arrangement,...
Abstract Nanostructuring is important for designing thermoelectrics. Yet, nanoprecipitates are thermodynamically unstable and coarsen through Ostwald ripening. Here, the ripening of Ag 2 Te in PbTe its resulting impact on thermoelectric performance investigated. Numerous Guinier‐Preston zones platelet precipitates sample quenched from a single‐phase region observed. Upon annealing, these grow into big lath‐shaped second phases by consuming small Ag‐rich clusters. The crystallographic...
Complex microstructures are found in many thermoelectric materials and can be used to optimize their transport properties. Grain boundaries particular scatter phonons, but they often impede charge carrier transfer at the same time. Designing grain order offer a conductive path for electrons is substantial opportunity thermoelectrics. Here, we demonstrate TiCoSb half Heusler compounds that Fe-dopants segregate simultaneously increase electrical conductivity reduce thermal conductivity. To...
Mg-Al-Ca alloys with Laves phase reinforcement are suitable for structural applications. The composition, crystal structure, and distribution of phases can be tuned by the alloy composition heat treatment, which subsequently influence their mechanical properties. In this study, three model Mg-6Al-2Ca, Mg-5Al-3Ca Mg-4Al-4Ca were investigated, include C15, C36, C14 phases. as-cast have interconnected that form a skeleton structure. After annealing, they became more rounded particles, while...
Abstract Dislocations and the residual strain they produce are instrumental for high thermoelectric figure of merit, zT ≈ 2, in lead chalcogenides. However, these materials tend to be brittle, barring them from practical green energy deep space applications. Nonetheless, bulk thermoelectrics research focuses on increasing without considering mechanical performance. Optimized always involve point defect concentrations doping solid solution alloying. Brittle show limited plasticity...
Thermoelectric (TE) materials are of utmost significance for conversion heat flux into electrical power in the low-power regime. Their efficiency depends strongly on microstructure. AgSbTe2-based compounds high-efficiency TE suitable mid-temperature range. Herein, we explore an Ag16.7Sb30Te53.3 alloy (at %) subjected to treatments at 380 °C different durations aimed nucleation and coarsening Sb2Te3-precipitates. To characterize Sb2Te3-precipitation, use a set methods combining thermal...
In a textured Mg thin film, two types of 〈0001〉 tilt grain boundaries are identified by electron microscopy and atomistic simulation. Coincidence site lattice dislocation models applied to study in hexagonal close-packed crystals.
Capturing and converting waste heat into electrical power through thermoelectric generators based on the Seebeck effect is a promising alternative energy source. Among compounds, PbTe can be alloyed form precipitates by aging at elevated temperatures, thus reducing thermal conductivity phonon scattering. Here, with Ag to Ag-rich having number density controlled treatments. We employ complementary scanning transmission electron microscopy atom probe tomography analyze precipitate PbTe-matrix...
Defects such as planar faults in thermoelectric materials improve their performance by scattering phonons with short and medium mean free paths (3–100 nm), thereby reducing the lattice thermal conductivity,κl. Understanding statistically microscopic distribution of these extended defects within grains low angle grain boundaries is necessary to tailor develop optimal for waste heat harvesting. Herein, we analyze from millimeter down nanometer scale a AgSbTe2 material boundaries. The...
Thin‐film materials libraries (MLs) in the system Cr–Al–B are synthesized on 100 mm diameter Al 2 O 3 sapphire substrates by combinatorial co‐sputtering from elemental targets at substrate temperatures of 600 and 700 °C to study phase formation MAB phases (M = transition metal, A A‐group element, B boron). The a mixture two Cr AlB 4 larger part ML prepared is observed X‐ray diffraction cross‐sectional transmission electron microscopy (TEM). Anisotropic growth large grains extending...
(Im-)miscible elemental combinations were co-sputtered on solid substrates and ionic liquids. The results reveal the formation mechanism of multinary NPs in liquids information concerning nanoscale miscibility.
Understanding the optical properties of lanthanide niobates is essential to improve development these materials. In this study, we investigated PrNbO4 powder particles with different density twins which influences intensity emission lines. The form during synthesis based on a solid-state route. A correlative approach using backscattered electron imaging, cathodoluminescence measurements, focused ion beam lift out, and aberration-corrected transmission microscopy was used at same location...