A5008573078- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Magnetic Properties of Alloys
- Multiferroics and related materials
- Physics of Superconductivity and Magnetism
- Shape Memory Alloy Transformations
- Dielectric properties of ceramics
- Rare-earth and actinide compounds
- Ferroelectric and Piezoelectric Materials
- Hydrogen Storage and Materials
- Additive Manufacturing Materials and Processes
- Metallic Glasses and Amorphous Alloys
- Heusler alloys: electronic and magnetic properties
- Inorganic Chemistry and Materials
- Electronic and Structural Properties of Oxides
- Magnetic Properties and Applications
- Crystallization and Solubility Studies
- Laser-Ablation Synthesis of Nanoparticles
- Metallurgical and Alloy Processes
- High Entropy Alloys Studies
- Laser-induced spectroscopy and plasma
- Advanced Materials Characterization Techniques
- Intermetallics and Advanced Alloy Properties
- X-ray Diffraction in Crystallography
- MXene and MAX Phase Materials
Technical University of Darmstadt
2017-2024
University of Augsburg
2009-2016
Institute of Experimental Physics of the Slovak Academy of Sciences
2014
Augsburg University
2008
Abstract The phase‐down scenario of conventional refrigerants used in gas–vapor compressors and the demand for environmentally friendly efficient cooling make search alternative technologies more important than ever. Magnetic refrigeration utilizing magnetocaloric effect magnetic materials could be that alternative. However, there are still several challenges to overcome before having devices competitive with those based on technology. In this paper a rigorous assessment most relevant...
Ni-Mn-based Heusler alloys, in particular all-d-metal Ni(-Co)-Mn-Ti, are highly promising materials for energy-efficient solid-state refrigeration as large multicaloric effects can be achieved across their magnetostructural martensitic transformation. However, no comprehensive study on the crucially important transition entropy change $\Delta s_t$ exists so far Ni(-Co)-Mn-Ti. Here, we present a systematic analyzing composition and temperature dependence of s_t$. Our results reveal...
We present a comprehensive study on three selected Heusler alloy systems. Ni‐Mn‐X(‐Co) systems with X = Al, In, Sn are compared respect to the relevant magnetocaloric properties of their magnetostructural phase transition, namely martensitic transition temperature as well its field dependence, magnetization change, and width thermal hysteresis. The latter one is strongly determining reversibility effect. Therefore understanding how tailor it by extrinsic intrinsic factors great importance....
Abstract The direct use of an advanced binder‐free additive manufacturing technique, namely laser powder bed fusion (L‐PBF), does not easily allow obtaining variously shaped, fully dense Nd–Fe–B magnets with high coercivity. process inherently leads to the re‐melting and appearance/disappearance undesired/desired microstructural features responsible for low large In this work, development a useful microstructure coercivity in Pr 21 Fe 73.5 Cu 2 B 3.5 Nd alloys possible way produce permanent...
A wide variety of properties such as half-metallicity is found among Heusler compounds. In order to separate intrinsic and extrinsic properties, high quality single crystals are required. Here, we report on differently grown the half-metallic ferromagnet Co2FeSi. All show excellent ordering, resulting in outstanding electrical behavior with low residual resistivity residual-resistivity-ratio. Co2FeSi a plateau below 50 K, which might point ferromagnetism. The cross-over from this unusual...
Additive manufacturing (AM) is an attractive processing route to make efficient use of rare-earth elements (REE) in systems containing complex-shaped (RE) based magnets. Powder bed fusion using laser beam (PBF-LB) one the most promising technologies obtain fully dense AM parts and has seen significant recent research efforts. However, works commercial Nd-Fe-B powders with a composition more suited for binder methods, which reduces parameter window does not allow property enhancement by...
Microstructure design allows to prevent intergranular cracking and premature failure in Co–Ni–Ga shape memory alloys. Favorable grain boundary configurations are established using additive manufacturing techniques, namely, direct energy deposition (DED) laser powder bed fusion (L‐PBF). L‐PBF establish a columnar structure. In the alloy processed by DED, microstructure with strong ⟨001⟩ texture is obtained. line optimized microstructures, general transformation behavior essential for...
A multi-stimuli cooling cycle can be used to increase the cyclic caloric performance of multicaloric materials like Ni-Mn-In Heusler alloys. However, use a uniaxial compressive stress as an additional external stimulus magnetic field requires good mechanical stability. Improvement stability and strength by doping has been shown in several studies. is always accompanied grain refinement change transition temperature. This raises question extent which related refinement, temperature, or...
In the solid-solution series La(y)Cu(3)RuxTi(4-x)O(12+δ) (0 ≤x≤ 4) Cu and Ru electronic states are highly correlated. With increasing content x system properties change from a paramagnetic insulator with colossal dielectric constant to heavy-fermion metal. To further elucidate occurring phase transitions, valences of have been investigated utilizing XANES measurements at Cu-K Ru-K absorption edges. It was found that oxidation number is close +4 in all samples, while valence linearly...
The phosphor CaTiO 3 :Pr 3+ was synthesized via a solid-state reaction in combination with subsequent annealing under flowing NH .Comparatively large off-center displacements of Ti the TiO 6 octahedra were confirmed for as-synthesized by XANES.Raman spectroscopy showed that local crystal structure becomes highly symmetric when powders are ammonolyzed at 400 °C.Rietveld refinement powder X-ray diffraction data revealed samples °C have smallest lattice strain and same time largest average...
Additive manufacturing (AM) is an attractive processing route to make efficient use of rare-earths in systems containing complex-shaped rare-earth based magnets. Powder bed fusion using laser beam (PBF-LB) one the most promising technologies obtain fully dense printed parts and has seen significant recent research. However, works commercial NdFeB-type powders with a composition more suited for binder AM methods, which reduces printing parameter window does not allow property enhancement by...
In article number 1901322, Tino Gottschall, Oliver Gutfleisch and co-workers present a rigorous assessment of the most promising magnetocaloric materials for solid-state refrigeration, providing comprehensive analysis their adiabatic temperature isothermal entropy changes under cycling in magnetic-field 1 2 T. Magnetic, calorimetric, heat transfer, criticality aspects are also considered.
The pulsed laser ablation in liquid (PLAL) is a simple, green, and cost-effective method for the synthesis of bimetallic nanoparticles. On basis this various material combinations within one particle are made possible, thus creating particles with unique physical chemical properties. Here, we investigate influence different pulse durations i.e., short (pico-second) long (nano-second), on structure Fe-Au particles. Detailed characterisation prepared two lasers gave interesting results terms...