Institute of Physics of Materials AS CR, v. v. i. > Groups > Multiscale Modelling and Measurements of Physical Properties

Multiscale Modelling and Measurements of Physical Properties

Headdoc. Ing. Roman Gröger, Ph.D.
E-mail [javascript protected email address]
Phone number+420 532 290 448
Room307



The main purpose of our research activities is to elucidate how functional properties of materials depend on their underlying atomic structure, types of crystal lattice defects and their spatial arrangement, dimensionality of nanostructures and surface properties. We currently focus on heteroepitaxial semiconductor films based on III-nitrides (2D structures, thickness 10-1000 nm), magnetic nanoparticles (Fe3O4, nanocubes 10-50 nm), aggregates of magnetic nanoparticles with low fractal dimensions (D <2) and macroscopic low-temperature behavior of transition metals. This research is carried out using a wide range of theoretical models (DFT, atomic models based on empirical and semi-empirical potentials, Monte Carlo, Landau-Ginzburg, cellular automata, Master equation), which are combined with experimental studies using electron microscopy (TEM, STEM, SEM, EBIC, EBSD), scanning probe microscopy (AFM, MFM, CPEM). We are developing several theoretical models for interpretations of the EBIC current, magnetic diffraction spectra, properties of magnetic nanoparticles and yield criteria for predictions of the onset of plastic deformation in bcc and hcp metals.



Research directions:



  • elucidation of the origin of threading dislocations in III-nitride semiconductor heterostructures

  • formulation of ionic-covalent semi-empirical potentials for studies of extended defects in III-nitrides

  • synthesis, characterization and functionalization of nanoparticles for biology

  • development of equipments for measurements of specific absorption rates of magnetic nanoparticles in alternating magnetic fields

  • characterization of functional properties of materials using TEM (STEM), SEM (EBSD, EBIC), SPM (AFM, MFM, nanoEBIC, CPEM)

  • theoretical models for interpretations of EBIC contrast and of magnetic neutron diffraction spectra

  • experimental and theoretical studies of plastic deformation of bcc metals (V, Nb, Ta, Mo, W) incl. the effects of magnetism (Cr, Fe), and of hcp metals (Mg)

  • elucidation of the mechanisms of plastic deformation in high entropy alloys CoCrFeMnNi and in precipitation-strengthened FeNiCr steels

  • formulation of mesoscopic models of self-organization and pattern formation in correlated microstructural domains


Collaborations



  • University of Cambridge (UK)

  • ON Semiconductor (Czechia, Belgium)

  • CzechNanoLab/CEITEC (Czechia)

  • Istituto Italiano di Tecnologia (Italy)

  • Paul Scherrer Institut (Switzerland)

  • University of Pennsylvania (USA)

  • ICAMS and Ruhr-Universität Bochum (Germany)

  • Materials Growth & Measurement Laboratory (Czechia)


Researchers


NamePhone numbersRoomsE-mail
Mgr. Jan Fikar, Ph.D. +420 532 290 455419 [javascript protected email address]
Mgr. Andrej Ostapovec, Ph.D. +420 532 290 429421 [javascript protected email address]
Mgr. Tereza Sojková, Ph.D. +420 532 290 451308 [javascript protected email address]

Visiting Scientists


NamePhone numbersRoomsE-mail
Dr. Matouš Mrovec +420 532 290 448307 [javascript protected email address]

Phd students


NamePhone numbersRoomsE-mail
Ing. Zuzana Šiška +420 532 290 451308 [javascript protected email address]
MSc. Nhu Quynh Thi Tran +420 532 290 451308 [javascript protected email address]
M.Tech. Ritu Verma +420 532 290 461427 [javascript protected email address]
M.Tech. Ankit Yadav +420 532 290 451308 [javascript protected email address]

Diploma students


NamePhone numbersRoomsE-mail
Mgr. Adam Fedor +420 532 290 451308 [javascript protected email address]
Bc. Matúš Lipták +420 532 290 451308 [javascript protected email address]


Project numberNameInvestigator
CZ.02.01.01/00/22_008/0004596 Sensors and Detectors for Future Information Society (SenDISo)doc. Ing. Roman Gröger, Ph.D.
24-12526S Exploitation of surface phenomena for elimination of extended defects in semiconductor nanostructuresdoc. Ing. Roman Gröger, Ph.D.

ALL PROJECTS


Project numberNameInvestigator
CZ.01.1.02/0.0/0.0/20_358/0023778 Correlative measurements of the magnetic properties of surfacedoc. Ing. Roman Gröger, Ph.D.
8J19UA037 Non-Schmid behavior of dislocations in magnesium and its alloysMgr. Andrej Ostapovec, Ph.D.
19-23411S Interplay of plasticity and magnetism in alpha-iron and chromiumdoc. Ing. Roman Gröger, Ph.D.
763685 BACK FOR THE FUTURE (CZ)doc. Ing. Roman Gröger, Ph.D.
LQ1601 CEITEC 2020prof. Ing. Luboš Náhlík, Ph.D.
CZ.1.05/1.1.00/02.0068 CEITEC – Central European Institute of Technologyprof. Ing. Luboš Náhlík, Ph.D.
P204/10/0255 Calculation of the Peierls barrier in bcc metals and its dependence on stressdoc. Ing. Roman Gröger, Ph.D.
Marie-Curie International Reintegration Grant (IRG), No. 247705 “MesoPhysDef” Mesoscopic framework for modeling physical processes in multiphase materials with defectsdoc. Ing. Roman Gröger, Ph.D.

ALL PROJECTS

MightyEBIC 2.0 (Ephemeron Labs)

Contact person: doc. Ing. Roman Gröger, Ph.D.
Scan controller and data acquisition interface for making quantitative Electron Beam Induced Current (EBIC) measurements.

SPM LiteScope (NenoVision)

Contact person: doc. Ing. Roman Gröger, Ph.D.
Scanning Probe Microscope (SPM) designed for easy integration into the Scanning Electron Microscopes. The combination of complementary AFM and SEM techniques enables to use the advantages of both commonly used microscopy techniques. LiteScope incorporates a unique imaging technique "Correlative Probe and Electron Microscopy (CPEM)" enabling simultaneous acquisition of AFM and SEM data. LiteScope and the CPEM technology allow sample analysis in a way that was previously difficult or impossible by the two imaging technologies simultaneously.

3D Printer Prusa i3 MKS3+ & MMU2S (Prusa Research)

Contact person: doc. Ing. Roman Gröger, Ph.D.
The Prusa i3 MK3S+ 3D printer is the successor to the successful MK2 model. The main advantages of the MK3S+ include a redesigned extruder, a range of sensors and smart features.


2024

Sojková T., Gröger R., Poloprudský J., Kuběna I., Schneeweiss O., Sojka M., Šiška Z., Pongrácz J., Pizúrová N.: Kinetics of spontaneous phase transitions from wüstite to magnetite in superparamagnetic core-shell nanocubes of iron oxides. Nanoscale 16 (2024) 5551-5560

Gröger R., Fikar J.: Nucleation of threading dislocations in atomistic simulations of strained layer epitaxy of III-nitrides. Acta Mater. 264 (2024) 119570

Tran N., Friák M., Miháliková I., Kiaba M., Hong N.: Profiles of oxygen and titanium point defects in ferromagnetic TiO2 films. Journal of Physics D: Applied Physics 57 (2024) 265302



2023

Kloenne Z., Couzinié J., Heczko M., Gröger R., Viswanathan G., Clark W., Fraser H.: On the bcc/B2 interface structure in a refractory high entropy alloy. Scr. Mater. 223 (2023) 115071

Ji Y., Frentrup M., Zhang X., Pongrácz J., Fairclough S., Liu Y., Zhu T., Oliver R.: Porous pseudo-substrates for InGaN quantum well growth: Morphology, structure, and strain relaxation. J. Appl. Phys. 134 (2023) 145102

Máthis K., Farkas A., Knapek M., Ostapovec A., Farkas G., Németh G., Harcuba P., Drozdenko D.: The influence of gadolinium concentration on the twin propagation rate in magnesium alloys. J. Alloys Comp. 948 (2023) 169635

Sojková T., Rizzo G., Di Girolamo A., Avugadda S., Soni N., Milbrandt N., Tsai Y., Kuběna I., Sojka M., Silvestri N., Samia A., Gröger R., Pellegrino T.: From core-shell FeO/Fe3O4 to magnetite nanocubes: Enhancing magnetic hyperthermia and imaging performance by thermal annealing. Chem. Mater. 35 (2023) 6201-6219

Gröger R., Holzer J., Kruml T.: Twinning and antitwinning in body-centered cubic metals. Comp. Mater. Sci. 216 (2023) 111874

Verma R., Ostapovec A.: On the interaction of migrating {11-26} twin boundary with nucleus of {10-12} twin in Mg at T -> 0 K. Low Temp. Phys. 49 (2023) 1257-1262

Pongrácz J., Vacek P., Gröger R.: Recombination activity of threading dislocations in MOVPE-grown AlN/Si {111} films etched by phosphoric acid. J. Appl. Phys. 134 (2023) 195704

Holzer J., Husťák M., Hegrová J., Gröger R.: Grain coarsening of columnar iron polycrystals by repetitive cold work and annealing. Metall. Mater. Trans. A 54 (2023) 439-449

Zelený M., Ostapovec A., Fridrich L., Šesták P., Heczko M., Kruml T.: On mechanical twinning in tetragonal lattice. Philos. Mag. 103 (2023) 119-136

Friák M., Tran N., Meduňa M., Gazdová K., Pavlů J., Munzar D., Hong N.: Vacancy-induced magnetic states in TiO2 surfaces. J. Appl. Phys. 134 (2023) 013902



2022

Holzer J., Gamanov Š., Luptáková N., Dlouhý A., Svoboda J.: Coarsening Kinetics of Y2O3 Dispersoid in New Grade of Fe-Al-Cr-Based ODS Alloy. Metals 12 (2022) 12020210

Pizúrová N., Buršík J., Sojková T., Roupcová P., Schneeweiss O.: Magnetic properties and morphology of ultra-small iron oxide nanoparticles. J. Phys.: Conf. Series 2315 (2022) 012023

Gröger R.: Origin of variable propensity for anomalous slip in body-centered cubic metals. Model. Simul. Mater. Sci. Eng. 30 (2022) 085007

Dymáček P., Kocich R., Kunčická L., Jarý M., Luptáková N., Holzer J., Mašek B., Svoboda J.: Processing of top creep and oxidation resistant Fe-Al based ODS alloys. Procedia Struct. Integr. 42 (2022) 1576-1583

Ostapovec A., Verma R., Serra A.: Unravelling the nucleation and growth of {1 1 -2 2} twins. Scr. Mater. 215 (2022) 114730

Vrchovecká K., Weiser A., Přibyl J., Kuta J., Holzer J., Pávková Goldbergová M., Sobola D., Dlouhý A.: A release of Ti-ions from nanostructured titanium oxide surfaces. Surfaces and Interfaces 29 (2022) 101699

Bajtošová L., Křivská ., Králík ., Veselý J., Hanuš J., Harcuba P., Fikar J., Yadav A., Cieslar M.: Deformation mechanisms of Al thin films: In-situ TEM and molecular dynamics study. Scr. Mater. 215 (2022) 114688

Gamanov Š., Holzer J., Roupcová P., Svoboda J.: High temperature oxidation kinetics of Fe 10Al 4Cr 4Y2O3 ODS alloy at 1200 1400 C. Corros. Sci. 206 (2022) 110498

Svoboda J., Gamanov Š., Bártková D., Luptáková N., Bořil P., Jarý M., Mašek B., Holzer J., Dymáček P.: The Optimization of Mechanical Alloying Conditions of Powder for the Preparation of a Fe-10Al-4Cr-4Y2O3 ODS Nanocoposite. Materials 15 (2022) 9034

Verma R., Král L., Ostapovec A.: Faceting of {11-26} twin interfaces in rolled pure magnesium. Philos. Mag. 102 (2022) 861-874

Svoboda J., Bořil P., Holzer J., Luptáková N., Jarý M., Mašek B., Dymáček P.: Substantial Improvement of High Temperature Strength of New-Generation Nano-Oxide-Strengthened Alloys by Addition of Metallic Yttrium. Materials 15 (2022) 15020504


all publications