Molecular Dynamics Simulation of Energetic Uranium Recoil Damage in Zircon
Defect production and amorphization due to energetic uranium recoils in zircon (ZrSiO4), which is a promising ceramic nuclear waste form, is studied using molecular dynamics simulations with a partial charge model. An algorithm that distinguishes between undamaged crystal, crystalline defects and amorphous regions is used to develop a fundamental understanding of the primary damage state. The amorphous cascade core is separated from the surrounding crystal by a defect-rich region. Small, chemically inhomogeneous amorphous clusters are also produced around the core. The amorphous regions consist of under-coordinated Zr and polymerized Si leading to amorphization and phase separation on a nanometer scale into Zr- and Si-rich regions. This separation could play an important role in the experimentally observed formation of nanoscale ZrO2 in ZrSiO4 irradiated at elevated temperatures.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 897677
- Report Number(s):
- PNNL-SA-50764; 3534b; 8208; KC0201020; TRN: US0701499
- Journal Information:
- Molecular Simulation, 32(12-13):1069-1077, Journal Name: Molecular Simulation, 32(12-13):1069-1077
- Country of Publication:
- United States
- Language:
- English
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