Schulz, T.; Remmele, T.; Markurt, T.; Korytov, M.; Albrecht, M.; Duff, A.; Lymperakis, L.; Neugebauer, J.: Alloy fluctuations in III-Nitrides revisited by aberration corrected transmission electron microscopy. International Workshop on Nitride Semiconductors 2012, Sapporo, Japan (2012)
Nazarov, R.; Hickel, T.; Neugebauer, J.: Consequences of H-Vacancy Interactions: An Ab Initio Insight. International Hydrogen Conference, Jackson Lake Lodge, Moran, WY, USA (2012)
Neugebauer, J.: Understanding H-embrittlement in high-strength steels by ab initio methods. 2012 International Hydrogen Conference, Moran, WY, USA (2012)
Neugebauer, J.: Density functional theory: From the chemical bond to microstructural information. Workshop Multiscale Material Modeling 2012, Bad Herrenalb, Germany (2012)
Race, C. P.; von Pezold, J.; Neugebauer, J.: Simulations of Grain Boundary Migration via the Nucleation and Growth of Islands. MSE Congress 2012, Darmstadt, Germany (2012)
Albrecht, M.; Markurt, T.; Schulz, T.; Lymperakis, L.; Duff, A.; Neugebauer, J.; Drechsel, P.; Stauss, P.: Dislocation Mechanisms and Strain Relaxation in the Growth of GaN on Silicon Substrates for Solid State Lighting. International Conference on Extended Defects in Semiconductors, Thessaloniki, Greek (2012)
Körmann, F.; Grabowski, B.; Hickel, T.; Neugebauer, J.: Advancing ab initio methods to finite temperatures: The opening of new routes in materials design. Seminar Talk at Institute on Quantum Materials Science, Yekaterinburg, Russia (2012)
Lymperakis, L.; Albrecht, M.; Neugebauer, J.: Excitonic emission from a-type screw dislocations in GaN. International Conference on Extended Defects in Semiconductors, Thessaloniki, Greek (2012)
Neugebauer, J.: Vacancy concentrations from 0K to the melting temperature in unary fcc metals: Discovery of large non-Arrhenius effects. CALPHAD 2012 Meeting, Berkeley, CA, USA (2012)
Dick, A.; Körmann, F.; Hickel, T.; Neugebauer, J.: Thermodynamic properties of cementite including magnetic, vibronic, and electronic excitations from ab initio. TMS Annual meeting 2012, Orlando, FL, USA (2012)
Hickel, T.; Sandschneider, N.; Friák, M.; Neugebauer, J.; Ouyang, Y.: Ab initio determination of point defects and derived diffusion properties in metals. TMS Annual meeting 2012, Orlando, FL, USA (2012)
In this project we study - together with the department of Prof. Neugebauer and Dr. Sandlöbes at RWTH Aachen - the underlying mechanisms that are responsible for the improved room-temperature ductility in Mg–Y alloys compared to pure Mg.
The wide tunability of the fundamental electronic bandgap by size control is a key attribute of semiconductor nanocrystals, enabling applications spanning from biomedical imaging to optoelectronic devices. At finite temperature, exciton-phonon interactions are shown to exhibit a strong impact on this fundamental property.
Oxides find broad applications as catalysts or in electronic components, however are generally brittle materials where dislocations are difficult to activate in the covalent rigid lattice. Here, the link between plasticity and fracture is critical for wide-scale application of functional oxide materials.
The project Hydrogen Embrittlement Protection Coating (HEPCO) addresses the critical aspects of hydrogen permeation and embrittlement by developing novel strategies for coating and characterizing hydrogen permeation barrier layers for valves and pumps used for hydrogen storage and transport applications.
Efficient harvesting of sunlight and (photo-)electrochemical conversion into solar fuels is an emerging energy technology with enormous promise. Such emerging technologies depend critically on materials systems, in which the integration of dissimilar components and the internal interfaces that arise between them determine the functionality.
Enabling a ‘hydrogen economy’ requires developing fuel cells satisfying economic constraints, reasonable operating costs and long-term stability. The fuel cell is an electrochemical device that converts chemical energy into electricity by recombining water from H2 and O2, allowing to generate environmentally-friendly power for e.g. cars or houses…
We have studied a nanocrystalline AlCrCuFeNiZn high-entropy alloy synthesized by ball milling followed by hot compaction at 600°C for 15 min at 650 MPa. X-ray diffraction reveals that the mechanically alloyed powder consists of a solid-solution body-centered cubic (bcc) matrix containing 12 vol.% face-centered cubic (fcc) phase. After hot compaction, it consists of 60 vol.% bcc and 40 vol.% fcc. Composition analysis by atom probe tomography shows that the material is not a homogeneous fcc–bcc solid solution