Holec, D.; Friák, M.; Dlouhy, A.; Neugebauer, J.: Ab initio study of pressure stabilized NiTi allotropes: Pressure-induced transformations and hysteresis loops. Physical Review B 84, pp. 224119-1 - 224119-8 (2011)
Grabowski, B.; Söderlind, P.; Hickel, T.; Neugebauer, J.: Temperature-driven phase transitions from first principles including all relevant excitations: The fcc-to-bcc transition in Ca. Physical Review B 84 (21), pp. 214107-1 - 214107-20 (2011)
Du, Y. J. A.; Ismer, L.; Rogal, J.; Hickel, T.; Neugebauer, J.; Drautz, R.: First-principles study on the interaction of H interstitials with grain boundaries in alpha- and gamma-Fe. Physical Review B 84 (14), pp. 144121-1 - 144121-13 (2011)
Dick, A.; Körmann, F.; Hickel, T.; Neugebauer, J.: Ab initio based determination of thermodynamic properties of cementite including vibronic, magnetic and electronic excitations. Physical Review B 84 (12), 125101 (2011)
Ismer, L.; Ireta, J.; Neugebauer, J.: A density functional theory based estimation of the anharmonic contributions to the free energy of a polypeptide helix. Journal of Chemical Physics 135 (8), pp. 084122-1 - 084122-7 (2011)
Marquardt, O.; Hickel, T.; Neugebauer, J.; Gambaryan, K. M.; Aroutiounian, V. M.: Growth process, characterization, and modeling of electronic properties of coupled InAsSbP nanostructures. Journal of Applied Physics 110 (4), pp. 043708-1 - 043708-6 (2011)
Grabowski, B.; Hickel, T.; Neugebauer, J.: Formation energies of point defects at finite temperatures. Physica Status Solidi B 248 (6), pp. 1295 - 1308 (2011)
Pfanner, G.; Freysoldt, C.; Neugebauer, J.: Ab initio study of electron paramagnetic resonance hyperfine structure of the silicon dangling bond: Role of the local environment. Physical Review B 83 (14), 144110, pp. 1 - 8 (2011)
Körmann, F.; Dick, A.; Hickel, T.; Neugebauer, J.: Role of spin quantization in determining the thermodynamic properties of magnetic transition metals. Physical Review B 83 (16), 165114 (2011)
von Pezold, J.; Lymperakis, L.; Neugebauer, J.: Hydrogen-enhanced plasticity at dilute bulk H concentrations: The role of H-H interactions and the formation of local hydrides. Acta Materialia 59, pp. 2969 - 2980 (2011)
Abbasi, A.; Dick, A.; Hickel, T.; Neugebauer, J.: First-principles investigation of the effect of carbon on the stacking fault energy of Fe–C alloys. Acta Materialia 59, pp. 3041 - 3048 (2011)
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.
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…
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.
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