Institute of Physics of Materials AS CR, v. v. i. > People > Gröger Roman

doc. Ing. Roman Gröger, Ph.D.

Room307
Phone number+420 532 290 448
E-mail[javascript protected email address]
Researcher IDG-3608-2010
Positionhead - Multiscale Modelling and Measurements of Physical Properties


2024

Bonneville J., Coupeau C., Douin J., Gröger R.: Screw dislocation dipoles in niobium: combination of STM observations and atomistic simulations. Model. Simul. Mater. Sci. Eng. 32 (2024) 065021

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

Pizúrová N., Gröger R.: Nanosvět, v němž je sekunda téměř věčností. Vesmír 103 (2024) 292-295

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



2023

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

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

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

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



2022

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



2021

Vacek P., Frentrup M., Lee L., Massabuau F., Kappers M., Wallis D., Gröger R., Oliver R.: Defect structures in (001) zincblende GaN/3C-SiC nucleation layers. J. Appl. Phys. 129 (2021) 155306

Holzer J., Chlup Z., Kruml T., Gröger R.: Plastic deformation of magnetically isotropic Cr single crystals compressed at 77 K. Int. J. Plast. 138 (2021) 102938

Gröger R., Šremr J., Vydrová J.: Uniqueness and stability of activated dislocation shapes in crystals. Model. Simul. Mater. Sci. Eng. 29 (2021) 025006

Gröger R.: Symmetry-adapted single crystal yield criterion for non-Schmid materials. Int. J. Plast. 146 (2021) 103101

Heczko M., Mazánová V., Gröger R., Záležák T., Hooshmand M., George E., Mills M., Dlouhý A.: Elemental segregation to lattice defects in the CrMnFeCoNi high-entropy alloy during high temperature exposures. Acta Mater. 208 (2021) 116719



2020

Antoš Z., Vacek P., Gröger R.: Intersections of two stacking faults in zincblende GaN. Comp. Mater. Sci. 180 (2020) 109620

Gröger R., Vítek V.: Single crystal yield criterion for chromium based on atomistic studies of isolated 1/2[111] screw dislocations. Int. J. Plast. 132 (2020) 102733

Gröger R., Vítek V., Dlouhý A.: Effective pair potential for random fcc CoCrFeMnNi alloys. Model. Simul. Mater. Sci. Eng. 28 (2020) 075006



2019

Gröger R., Vítek V.: Impact of non-Schmid stress components present in the yield criterion for bcc metals on the activity of {110}<111> slip systems. Comp. Mater. Sci. 159 (2019) 297-305

Heczko M., Esser B., Gröger R., Feng L., Mazánová V., Wang Y., Mills M.: Structure, Morphology and Coarsening Behavior of MX (NbC) Nanoprecipitates in Fe-Ni-Cr Based Alloys. Microscopy and Microanalysis 25 (2019) 2612-2613

Vacek P., Kostelník P., Gröger R.: Correlation of Structure and EBIC Contrast from Threading Dislocations in AlN/Si Films. Phys. Stat. Sol. B 256 (2019) 1900279

Gröger R., Chlup Z., Sojková T., Kuběna I.: Interplay of slip and twinning in niobium single crystals compressed at 77 K. J. Mater. Res. 34 (2019) 261-270



2018

Gröger R., Chlup Z., Kuběna I., Kruml T.: Slip activity in molybdenum single crystals compressed at 77 K. Philos. Mag. 98 (2018) 2749-2768

Gröger R., Chlup Z., Sojková T.: Deformation twinning in vanadium single crystals tested in compression at 77 K. Mater. Sci. Eng. A 737 (2018) 413-421



2017

Fikar J., Gröger R., Schäublin R.: Interaction of irradiation-induced prismatic dislocation loops with free surfaces in tungsten. Nucl. Instr. Meth. Phys. Res. B 393 (2017) 186-189

Fikar J., Gröger R., Schäublin R.: Effect of orientation of prismatic dislocation loops on interaction with free surfaces in BCC iron. J. Nucl. Mater. 497 (2017) 161-165

Gröger R., Vítek V., Lookman T.: Mesoscale plastic texture in body-centered cubic metals under uniaxial load. Phys. Rev. Mater. 1 (2017) 063601

Hernandez-Maldonado D., Gröger R., Ramasse Q., Hirsch P., Nellist P.: Evaluation of aberration-corrected optical sectioning for exploring the core structure of 1/2[111] screw dislocations in BCC metals. Microscopy and Microanalysis 23 (2017) 432-433



2016

Gröger R., Lookman T.: Mesoscopic description of dislocation patterning using the concept of incompatibility of strains. Solid State Phenom. 258 (2016) 87-92

Gröger R., Marchand B., Lookman T.: Dislocations via incompatibilities in phase-field models of microstructure evolution. Phys. Rev. B 94 (2016) 054105

Fikar J., Gröger R.: Shape of small prismatic dislocation loops in tungsten and iron. Solid State Phenom. 258 (2016) 97-101

Hernandez-Maldonado D., Yang H., Jones L., Gröger R., Hirsch P., Ramasse Q., Nellist P.: STEM optical sectioning for imaging screw dislocations core structures in BCC metals. Microscopy and Microanalysis 22 (2016) 1932-1933



2015

Fikar J., Gröger R.: Interactions of prismatic dislocation loops with free surfaces in thin foils of body-centered cubic iron. Acta Mater. 99 (2015) 392-401

Gröger R., Leconte L., Ostapovec A.: Structure and stability of threading edge and screw dislocations in bulk GaN. Comp. Mater. Sci. 99 (2015) 195-202

Ostapovec A., Buršík J., Gröger R.: Deformation due to migration of faceted twin boundaries in magnesium and cobalt. Philos. Mag. 95 (2015) 4106-4117

Gröger R., Vítek V.: Determination of positions and curved transition pathways of screw dislocations in BCC crystals from atomic displacements. Mater. Sci. Eng. A 643 (2015) 203-210



2014

Ostapovec A., Molnár P., Gröger R.: On basal-prismatic twinning interfaces in magnesium. IOP Conf. Ser.: Mater. Sci. Eng. 63 (2014) 012134

Gröger R.: Thermodynamics of dislocation pattern formation at the mesoscale. Key Eng. Mater. 592-593 (2014) 79-82

Ostapovec A., Gröger R.: Twinning disconnections and basal-prismatic twin boundary in magnesium. Model. Simul. Mater. Sci. Eng. 22 (2014) 025015

Gröger R.: Which stresses affect the glide of screw dislocations in bcc metals?. Philos. Mag. 94 (2014) 2021-2030



2013

Gröger R., Vítek V.: Stress dependence of the Peierls barrier of 1/2<111> screw dislocations in bcc metals. Acta Mater. 61 (2013) 6362-6371

Srivastava K., Gröger R., Weygand D., Gumbsch P.: Dislocation motion in tungsten: Atomistic input to discrete dislocation simulations. Int. J. Plast. 47 (2013) 126-142



2012

Gröger R., Vítek V.: Constrained Nudged Elastic Band calculation of the Peierls barrier with atomic relaxations. Model. Simul. Mater. Sci. Eng. 20 (2012) 035019



2011

Gröger R., Lookman T.: Influence of dislocations on the spatial variation of microstructure in martensites. Key Eng. Mater. 465 (2011) 77-80

Gröger R., Dudeck K., Nellist P., Vítek V., Hirsch P., Cockayne D.: Effect of Eshelby twist on core structure of screw dislocations in molybdenum: Atomic structure and electron microscope image simulations. Philos. Mag. 91 (2011) 2364



2010

Gröger R., Lookman T., Saxena A.: Incompatibility of strains and its application to mesoscopic studies of plasticity. Phys. Rev. B 82 (2010) 144104



2009

Gröger R., Lookman T., Saxena A.: Atomistic studies of transformation pathways and energetics in plutonium. Philos. Mag. 89 (2009) 1779-1792

Gröger R., Vítek V.: Directional versus central-force bonding in studies of the structure and glide of 1/2<111> screw dislocations in bcc transition metals. Philos. Mag. 89 (2009) 3163-3178

Gröger R., Vítek V.: Temperature and strain rate dependent flow criterion for bcc transition metals based on atomistic analysis of dislocation glide. Int. J. Mater. Res. 100 (2009) 315-321



2008

Gröger R., Vítek V.: Multiscale modeling of plastic deformation of molybdenum and tungsten: III. Effects of temperature and plastic strain rate. Acta Mater. 56 (2008) 5426-5439

Gröger R., Racherla V., Bassani J., Vítek V.: Multiscale modeling of plastic deformation of molybdenum and tungsten: II. Yield criterion for single crystals based on atomistic studies of glide of 1/2<111> screw dislocations. Acta Mater. 56 (2008) 5412-5425

Gröger R., Lookman T., Saxena A.: Defect-induced incompatibility of elastic strains: Dislocations within the Landau theory of martensitic phase transformations. Phys. Rev. B 78 (2008) 184101

Gröger R., Bailey A., Vítek V.: Multiscale modeling of plastic deformation of molybdenum and tungsten: I. Atomistic studies of the core structure and glide of 1/2<111> screw dislocations at 0 K. Acta Mater. 56 (2008) 5401-5411



2007

Gröger R., Vítek V.: Explanation of the discrepancy between the theoretical and measured yield stresses in body-centered cubic metals. Philos. Mag. Lett. 87 (2007) 113-120

Mrověc M., Gröger R., Bailey A., Nguyen-Manh D., Elsässer C., Vítek V.: Bond-order potential for simulations of extended defects in tungsten. Phys. Rev. B 75 (2007) 104119



2005

Nguyen-Manh D., Cawkwell M., Gröger R., Mrověc M., Pořízek R., Pettifor D., Vítek V.: Dislocations in materials with mixed covalent and metallic bonding. Mater. Sci. Eng. A 400-401 (2005) 68-71

Gröger R., Vítek V.: Breakdown of the Schmid law in bcc molybdenum related to the effect of shear stress perpendicular to the slip direction. Mater. Sci. Forum 482 (2005) 123-126



2004

Vítek V., Mrověc M., Gröger R., Bassani J., Racherla V., Yin L.: Effects of non-glide stresses on the plastic flow of single and polycrystals of molybdenum. Mater. Sci. Eng. A 387-389 (2004) 138-142


Number of ProjectName
CZ.02.01.01/00/22_008/0004596 Sensors and Detectors for Future Information Society (SenDISo)
24-12526S Exploitation of surface phenomena for elimination of extended defects in semiconductor nanostructures
CZ.01.1.02/0.0/0.0/20_358/0023778 Correlative measurements of the magnetic properties of surface
19-23411S Interplay of plasticity and magnetism in alpha-iron and chromium
763685 BACK FOR THE FUTURE (CZ)
16-13797S Origin and mechanism of anomalous slip in non-magnetic bcc metals
P204/10/0255 Calculation of the Peierls barrier in bcc metals and its dependence on stress
Marie-Curie International Reintegration Grant (IRG), No. 247705 “MesoPhysDef” Mesoscopic framework for modeling physical processes in multiphase materials with defects