Ústav fyziky materiálů AV ČR, v. v. i. > Zaměstnanci > Gröger Roman

doc. Ing. Roman Gröger, Ph.D.

Místnost307
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Researcher IDG-3608-2010
Pozicevedoucí - Víceúrovňové modelování a měření fyzikálních vlastností


2024

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

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



2023

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

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



2022

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



2021

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

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



2020

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

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



2019

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

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



2018

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

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



2017

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

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



2016

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

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



2015

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

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



2014

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

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



2013

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

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



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., 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

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



2008

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

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



2007

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

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



2005

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

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



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


ČísloNázev
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CZ.01.1.02/0.0/0.0/20_358/0023778 Korelativní měření magnetických vlastností povrchů
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763685 BACK FOR THE FUTURE (CZ)
16-13797S Původ a mechanismus anomálního skluzu v nemagnetických bcc kovech
P204/10/0255 Výpočet Peierlsovy bariéry v bcc kovech a její závislosti na napětí
Marie-Curie International Reintegration Grant (IRG), No. 247705 “MesoPhysDef” Mezoskopický rámec pro modelování fyzikálních procesů ve vícefázových materiálech s defekty