Publications

2026

  • Li, Y., Maron, M., Baker, K., Flores, B. R., Black, T., Hollenbeck, J., Lalani, I., Ghoniem, N., & Po, G. (2026). Coupled cluster and dislocation dynamics modeling of microstructure evolution in irradiated materials. Journal of the Mechanics and Physics of Solids, 206, 106366. https://doi.org/10.1016/j.jmps.2025.106366
    Abstract

    We develop here a coupled cluster and dislocation dynamics framework to study the microstructure evolution of irradiated materials. The framework not only accounts for the three dimensional diffusion of radiation-generated clusters, but also their interaction with dislocation networks and the resultant climb motion of discrete dislocations within finite crystals. The framework is solved with a superposition solution scheme, and is applied to investigate the evolution of the irradiation-induced dislocation loops in zirconium (Zr), considering the effects of various bias factors including the diffusion anisotropy difference (DAD) of interstitials and interstitial clusters, the dislocation bias of defects to discrete dislocation segments, and the production bias of defects from the radiation cascade. We find that the DAD is the most critical factor influencing the kinetics of the loop evolution in Zr, while the recombination/interaction of mobile defects can induce a strong spatial dependence of the loop evolution together with the DAD. The method is also adopted to study the evolution of interstitial 〈a〉 and vacancy 〈c〉 dislocation loop ensembles consistent with the microstructure observed during irradiation-induced growth of Zr. Our findings not only reveal the spatial dependence of the size and ellipticity of the dislocation loops, but also suggest a limit on the anisotropy factor of interstitials to reproduce the co-growth of 〈a〉 and 〈c〉 loops in zirconium, in good agreement with experimental observations and other simulation results.

    BibTeX
    @article{LI2026106366,
  title = {Coupled cluster and dislocation dynamics modeling of microstructure evolution in irradiated materials},
  journal = {Journal of the Mechanics and Physics of Solids},
  volume = {206},
  pages = {106366},
  year = {2026},
  issn = {0022-5096},
  url = {https://doi.org/10.1016/j.jmps.2025.106366},
  doi = {10.1016/j.jmps.2025.106366},
  author = {Li, Yang and Maron, Matthew and Baker, Kristopher and Flores, Benjamin Ramirez and Black, Thomas and Hollenbeck, James and Lalani, Inam and Ghoniem, Nasr and Po, Giacomo},
  keywords = {Cluster diffusion, Dislocation climb, Bias factors, Irradiation growth}
}

2025

  • Peng, J., & Cereceda, D. (2025). Temperature-Dependent Mechanical and Electronic Properties of 3C-SiC: Insights From First-Principles Calculations. Journal of Applied Mechanics, 92(11), 111009. https://doi.org/10.1115/1.4069107
    Abstract

    The zinc-blende polytype of silicon carbide, known as 3C-SiC, is a promising ceramic material in high-temperature energy applications. However, the reported data on its mechanical and electronic properties, especially at elevated temperatures, are either lacking or scarce, with sizeable uncertainty. In this study, we present a comprehensive study on the temperature-dependent mechanical and electronic properties of 3C-SiC. First-principles calculations are combined with the quasi-harmonic approximation to investigate lattice properties at elevated temperature. We find that phonons dominate the temperature-dependent behavior. As temperature increases, all elastic constants exhibit a softening trend, and 3C-SiC becomes more elastically anisotropic. Our calculated degree of softening of elasticity is weaker than the values reported by previous studies. Moreover, the effects of thermal expansion and electron–phonon coupling on the electron band energy at elevated temperatures are investigated. The electron–phonon coupling dominates the temperature dependence of the band gap, where 3C-SiC maintains its wide gap at high temperature.

    BibTeX
    @article{10.1115/1.4069107,
  author = {Peng, Jie and Cereceda, David},
  title = {Temperature-Dependent Mechanical and Electronic Properties of 3C-SiC: Insights From First-Principles Calculations},
  journal = {Journal of Applied Mechanics},
  volume = {92},
  number = {11},
  pages = {111009},
  year = {2025},
  month = aug,
  issn = {0021-8936},
  doi = {10.1115/1.4069107},
  url = {https://doi.org/10.1115/1.4069107},
  eprint = {https://asmedigitalcollection.asme.org/appliedmechanics/article-pdf/92/11/111009/7519253/jam-25-1191.pdf}
}
  • Ullah, R., Morgan, D. D., & Szlufarska, I. (2025). Mg and native defects in cubic silicon carbide from first principles. Journal of Physics D: Applied Physics, 58(26), 265302. https://doi.org/10.1088/1361-6463/ade263
    Abstract

    The diffusion of Mg defects in 3C-SiC is studied using the density functional theory. Mg has the highest burn-in rate as a transmutant in 3C-SiC when it is placed in high-energy neutron irradiation environment of a fusion reactor. The presence and evolution of transmutant defects impact thermal and mechanical properties of this important structural material. This study is focused on understanding the structure, stability, and evolution of Mg defects and the interaction of Mg with native defects in 3C-SiC. Our calculations of diffusion coefficients for different Mg defects suggest that Mg is likely to diffuse faster in pristine 3C-SiC than in the damaged one, in agreement with earlier experimental observations.

    BibTeX
    @article{Ullah_2025,
  doi = {10.1088/1361-6463/ade263},
  url = {https://doi.org/10.1088/1361-6463/ade263},
  year = {2025},
  month = jun,
  publisher = {IOP Publishing},
  volume = {58},
  number = {26},
  pages = {265302},
  author = {Ullah, Rafi and Morgan, Dane D and Szlufarska, Izabela},
  title = {Mg and native defects in cubic silicon carbide from first principles},
  journal = {Journal of Physics D: Applied Physics}
}

2024

  • Maron, M., Li, Y., Lalani, I., Baker, K., Flores, B. R., Black, T., Hollenbeck, J., Ghoniem, N., & Po, G. (2024). Spatially-resolved cluster dynamics modeling of irradiation growth. International Journal of Plasticity, 177, 103989. https://doi.org/10.1016/j.ijplas.2024.103989
    Abstract

    We develop here a spatially resolved, three-dimensional continuum model coupling cluster dynamics (SR-CD) and crystal plasticity to investigate irradiation growth in zirconium. The model uses scale separation to divide the population of the irradiation cluster into mobile and immobile families. Small interstitial and vacancy clusters are modeled using anisotropic reaction–diffusion equations. Among the immobile clusters, an atomistically-informed vacancy cluster to vacancy loop transition is taken into account. The coupling between the evolution equation of CD and the plastic deformation of the material is two-fold, with stress-informed bias factors and local inelastic strains computed from the evolution of the evolving cluster population. The numerical implementation of the model utilizes the finite element method to analyze both single-crystal and polycrystalline samples. The growth strains that are computed align well with the experimental data provided by Carpenter for single-crystal Zr. Furthermore, the transformation of a vacancy cluster into a complete vacancy loop, occurring at a size of 14 nm, is in agreement with experimental observations and atomistic simulations. The density, size, and growth rate of the dislocation loops, denoted as 〈c〉 and 〈a〉, also exhibit good agreement with transmission electron microscopy (TEM) analysis of irradiated Zr and its alloys. Our findings demonstrate that there is a spatial correlation between the growth of these dislocation loops and growth strains, significantly influenced by the crystal size. To explain the expansion of the 〈a〉 axis and the contraction of the 〈c〉 axis in irradiated Zr, it is necessary to consider the diffusion anisotropy difference (DAD) of mobile interstitial species. We show that the PWR Kearns parameters, specifically fr = 0.63, ft = 0.32, fa = 0.05, confer enhanced irradiation resistance to Zr along the principal directions when compared to single crystals. Additionally, reducing the grain size to nanograins further enhances the resistance to irradiation-induced growth, particularly along the direction with the highest volume fraction of basal poles [0001].

    BibTeX
    @article{Maron-2024-src,
  title = {Spatially-resolved cluster dynamics modeling of irradiation growth},
  journal = {International Journal of Plasticity},
  volume = {177},
  pages = {103989},
  year = {2024},
  month = jun,
  issn = {0749-6419},
  doi = {10.1016/j.ijplas.2024.103989},
  url = {https://www.sciencedirect.com/science/article/pii/S0749641924001165},
  author = {Maron, Matthew and Li, Yang and Lalani, Inam and Baker, Kristopher and Flores, Benjamin Ramirez and Black, Thomas and Hollenbeck, James and Ghoniem, Nasr and Po, Giacomo},
  keywords = {Spatially resolved, Cluster dynamics, Crystal plasticity, Polycrystal, Irradiation growth, Zirconium}
}

Presentations

2025

  • Gehrig, M. L., & Humrickhouse, P. W. (2025). Computational Investigation of Radiation-Induced Microstructure Changes on Tritium Transport in Fusion Materials. Talk, 14th International Conference on Tritium Science and Technology (Tritium 2025).
    BibTeX
    @misc{Gehrig2025Computational,
  author = {Gehrig, Monica L. and Humrickhouse, Paul W.},
  title = {Computational Investigation of Radiation-Induced Microstructure Changes on Tritium Transport in Fusion Materials},
  howpublished = {Talk, 14th International Conference on Tritium Science and Technology (Tritium 2025)},
  address = {Ottawa, Ontario, Canada},
  month = sep,
  year = {2025}
}
  • Maron, M., Li, Y., & Po, G. (2025). Coupled Cluster and Dislocation Dynamics Modeling of Irradiation Creep and Growth. Keynote talk, XVIII International Conference on Computational Plasticity: Fundamentals and Applications (COMPLAS 2025).
    Abstract

    We develop a coupled Dislocation Dynamics and Cluster Dynamics model of irradiation creep and growth. The model couples spatially dependent reaction-diffusion boundary value problems (BVP) for mobile vacancy and SIA clusters to the evolution of the discrete dislocation network within the crystal, including climb and glide motion of dislocations. Glide mobility laws are implemented through a neural network which was trained by Molecular Dynamics simulations, while climb motion is determined by the flux of mobile defects into the dislocation core. The framework is implemented in three-dimensional discrete dislocation dynamics (DDD) simulations within a superposition solution scheme, and it considers the effects of various bias factors including the diffusion anisotropy difference (DAD) of SIA clusters, the dislocation bias, and the production bias of defects from the radiation cascade. The framework is applied to model the high-temperature deformation of irradiated materials, with emphasis on irradiation creep and growth in both fission and fusion conditions. In irradiation growth conditions in Zr, we find that the DAD is the most critical factor influencing the kinetics of the loop evolution, while the recombination/interaction of mobile defects induces a strongly spatial dependence of the loop evolution. The method is also adopted to study the evolution of interstitial ⟨a⟩ and vacancy ⟨c⟩ dislocation loop ensembles in Zr. Our findings reveal the spatial dependence of the growth, and it determines a specific range for the anisotropy factor of SIA clusters to reproduce the co-growth of ⟨a⟩ and ⟨c⟩ loops.

    BibTeX
    @misc{Maron2025CoupledCluster,
  author = {Maron, Matthew and Li, Yang and Po, Giacomo},
  title = {Coupled Cluster and Dislocation Dynamics Modeling of Irradiation Creep and Growth},
  howpublished = {Keynote talk, XVIII International Conference on Computational Plasticity: Fundamentals and Applications (COMPLAS 2025)},
  month = sep,
  year = {2025},
  note = {https://complas2025.cimne.com/event/contribution/d9c5b73c-0666-11f0-9835-000c29ddfc0c}
}
  • Cusentino, M. A., Manzoor, A., Jin, Y., Spencer, T., Pitike, K. C., Setyawan, W., Ullah, R., Szlufarska, I., Trelewicz, J. R., & Marian, J. (2025). Development of Machine Learned Interatomic Potentials for Modeling Transmutation Products in Fusion First Wall Materials. Talk, 2025 TMS Annual Meeting & Exhibition. https://doi.org/10.2172/3023901
    BibTeX
    @misc{Cusentino2025MachineLearnedPotentials,
  author = {Cusentino, Mary Alice and Manzoor, Anus and Jin, Yusheng and Spencer, Thomas and Pitike, Krishna C. and Setyawan, Wahyu and Ullah, Rafi and Szlufarska, Izabela and Trelewicz, Jason R. and Marian, Jaime},
  title = {Development of Machine Learned Interatomic Potentials for
                    Modeling Transmutation Products in Fusion First Wall Materials},
  howpublished = {Talk, 2025 TMS Annual Meeting \& Exhibition},
  month = mar,
  year = {2025},
  note = {Presented March 26, 2025, in the symposium ``Meeting Materials
                    Challenges for the Future of Fusion Energy,'' Las Vegas,
                    Nevada, USA. SAND2025-03199C},
  url = {https://www.osti.gov/biblio/3023901},
  doi = {10.2172/3023901}
}
  • Manzoor, A., Thomas, S., & Trelewicz, J. (2025). Effect of Transmutation Products on Point Defect Energies in Tungsten From First-Principles and Machine Learning. Talk, 2025 TMS Annual Meeting & Exhibition.
    BibTeX
    @misc{Manzoor:2025:ETP,
  author = {Manzoor, Anus and Thomas, Spencer and Trelewicz, Jason},
  howpublished = {Talk, 2025 TMS Annual Meeting \& Exhibition},
  month = mar,
  year = {2025},
  title = {Effect of Transmutation Products on Point Defect Energies in Tungsten From First-Principles and Machine Learning}
}
  • Abaalkhail, A. K., Dudhatra, H., German, P., Marian, J., Spencer, B., & Po, G. (2025). A Microstructure-Based Viscoplastic Model of FW & Blanket Fusion Materials. Poster, ICFRM-22: International Conference on Fusion Reactor Materials, Shizuoka, Japan, Sep 28–Oct 3, 2025.
    BibTeX
    @misc{abaalkhail2025-fw-blanket,
  author = {Abaalkhail, Abdulmohssen K. and Dudhatra, Harsh and German, Peter and Marian, Jamie and Spencer, Benjamin and Po, Giacomo},
  howpublished = {Poster, ICFRM-22: International Conference on Fusion Reactor Materials, Shizuoka, Japan, Sep 28--Oct 3, 2025},
  title = {A Microstructure-Based Viscoplastic Model of {FW} \& Blanket Fusion Materials},
  year = {2025},
  month = {28 Sep -- 3 Oct}
}
  • Marian, J., Trelewicz, J., & Bernholdt, D. (2025). Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation: ThermChem-FW. Invited talk, 2025 SciDAC-5 Principal Investigator (PI) Meeting, Rockville, Maryland. https://thermchem-fw.github.io/assets/documents/2025-09-marian-scidac-pi-meeting.pdf
    BibTeX
    @misc{2025-09-marian-scidac-pi-meeting,
  author = {Marian, Jaime and Trelewicz, Jason and Bernholdt, David},
  howpublished = {Invited talk, 2025 SciDAC-5 Principal Investigator (PI) Meeting, Rockville, Maryland},
  title = {Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation: ThermChem-FW},
  year = {2025},
  month = {16--18 September}
}

2024

  • Marian, J., & Trelewicz, J. (2024). Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation: ThermChem-FW. Invited talk, 2024 SciDAC-5 Principal Investigator (PI) Meeting, Rockville, Maryland. https://thermchem-fw.github.io/assets/documents/2024-07-marian-scidac-pi-meeting.pdf
    BibTeX
    @misc{2024-07-marian-scidac-pi-meeting,
  author = {Marian, Jaime and Trelewicz, Jason},
  howpublished = {Invited talk, 2024 SciDAC-5 Principal Investigator (PI) Meeting, Rockville, Maryland},
  title = {Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation: ThermChem-FW},
  year = {2024},
  month = {16--18 July}
}

Other Documents

2023

  • Marian, J., Trelewicz, J., Szlufarska, I., Po, G., Cereceda, D., Cusentino, M. A., Sargsyan, K., Setyawan, W., Bernholdt, D., Humrickhouse, P., Permann, C., & Spencer, B. (2023). Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation (ThermChem-FW). Proposal to the U. S. Dept. of Energy, Office of Science, Office of Fusion Energy Sciences and Office of Advanced Scientific Computing Research, funding opportunity announcement DE-FOA-0002924, Scientific Discovery Through Advanced Computing (SCiDAC) - FES Partnerships. https://thermchem-fw.github.io/assets/documents/thermochem-fw-proposal-2023.pdf
    BibTeX
    @misc{thermochem-fw-proposal-2023,
  author = {Marian, Jaime and Trelewicz, Jason and Szlufarska, Izabela and Po, Giacomo and Cereceda, David and Cusentino, Mary Alice and Sargsyan, Khachik and Setyawan, Wahyu and Bernholdt, David and Humrickhouse, Paul and Permann, Cody and Spencer, Benjamin},
  howpublished = {Proposal to the U. S. Dept. of Energy, Office of Science, Office of Fusion Energy Sciences and Office of Advanced Scientific Computing Research, funding opportunity announcement DE-FOA-0002924, Scientific Discovery Through Advanced Computing (SCiDAC) - FES Partnerships},
  title = {Integrated Thermomechanical Model of First Wall Components Under Evolving Chemistry and Microstructure During Fusion Reactor Operation  (ThermChem-FW)},
  year = {2023},
  note = {Note: this version does not include scope changes in response to budget changes at award time.}
}