Lymperakis, L.: Surface rehybridization and strain effects on the composition and the properties of ternary III Nitride alloys. 19th International Conference on Crystal Growth and Epitaxy, Keystone, CO, USA (2019)
Lymperakis, L.: Elastically Frustrated Rehybridization: Implications in Alloy Ordering and Strong Compositional Limitations in Epitaxial InGaN Films. 1st German Austrian Conference of Crystal Growth, Vienna, Austria (2018)
Lymperakis, L.: Physics, growth mechanisms, and peculiarities of III-N surfaces from ab-initio. Seminar at Institute for solid state physics, Technical University Berlin, Berlin, Germany (2017)
Lymperakis, L.: Elastically frustrated rehybridization of InGaN surfaces: Implications on growth temperature and alloy ordering. Spring school on short period superlattices, Warsaw, Poland (2017)
Lymperakis, L.: Epitaxial Growth of III-Nitrides: Insights from Density Functional Theory Calculations. Seminar at University of Crete, Physics Department, Crete, Greece (2016)
Lymperakis, L.: Interplay of kinetics and thermodynamics of epitaxially grown wide bandgap semiconductors. 10th Asian-European Conference on Plasma Surface Engineering, Jeju Island, South Korea (2015)
Lymperakis, L.; Weidlich, P. H.; Eisele, H.; Schnedler, M.; Nys, J.-P.; Grandidier, B.; Stievenard, D.; Dunin-Borkowski, R.; Neugebauer, J.; Ebert, P.: Revealing Hidden Surface States of Non-Polar GaN Facets by an Ab Initio Tailored STM Approach. 10th International Conference on Nitride Semiconductors, Washigton DC, USA (2013)
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)
Lymperakis, L.: Ab initio calculations of energetics, adatom kinetics, and electronic structure of nonpolar and semipolar III-Nitride surfaces. PolarCoN Summer School, Kostanz, 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)
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)
von Pezold, J.; Lymperakis, L.; Neugebauer, J.: Towards an ab-initio based understanding of H-embrittlement: An atomistic study of the HELP mechanism. Joint Hydrogenius and ICNER International Workshop on Hydrogen-Materials Interactions, Kyushu, Japan (2012)
Duff, A.; Lymperakis, L.; Neugebauer, J.: Ab-initio based comparitive study of In incorporation and surface segregation on III- and N-face {0001} InGaN surfaces. 9th International Conference of Nitride Semi-Conductors, Glasgow, UK (2011)
Hydrogen in aluminium can cause embrittlement and critical failure. However, the behaviour of hydrogen in aluminium was not yet understood. Scientists at the Max-Planck-Institut für Eisenforschung were able to locate hydrogen inside aluminium’s microstructure and designed strategies to trap the hydrogen atoms inside the microstructure. This can…
Hydrogen induced embrittlement of metals is one of the long standing unresolved problems in Materials Science. A hierarchical multiscale approach is used to investigate the underlying atomistic mechanisms.
For understanding the underlying hydrogen embrittlement mechanism in transformation-induced plasticity steels, the process of damage evolution in a model austenite/martensite dual-phase microstructure following hydrogenation was investigated through multi-scale electron channelling contrast imaging and in situ optical microscopy.
We will investigate the electrothermomechanical response of individual metallic nanowires as a function of microstructural interfaces from the growth processes. This will be accomplished using in situ SEM 4-point probe-based electrical resistivity measurements and 2-point probe-based impedance measurements, as a function of mechanical strain and…
The project aims to study corrosion, a detrimental process with an enormous impact on global economy, by combining denstiy-functional theory calculations with thermodynamic concepts.
Hydrogen embrittlement affects high-strength ferrite/martensite dual-phase (DP) steels. The associated micromechanisms which lead to failure have not been fully clarified yet. Here we present a quantitative micromechanical analysis of the microstructural damage phenomena in a model DP steel in the presence of hydrogen.
This project will aim at developing MEMS based nanoforce sensors with capacitive sensing capabilities. The nanoforce sensors will be further incorporated with in situ SEM and TEM small scale testing systems, for allowing simultaneous visualization of the deformation process during mechanical tests
Understanding hydrogen-assisted embrittlement of advanced structural materials is essential for enabling future hydrogen-based energy industries. A crucially important phenomenon in this context is the delayed fracture in high-strength structural materials. Factors affecting the hydrogen embrittlement are the hydrogen content,...
Thermo-chemo-mechanical interactions due to thermally activated and/or mechanically induced processes govern the constitutive behaviour of metallic alloys during production and in service. Understanding these mechanisms and their influence on the material behaviour is of very high relevance for designing new alloys and corresponding…