|About this Abstract
||2023 TMS Annual Meeting & Exhibition
||Ceramic Materials for Nuclear Energy Research and Applications
||Impact of Resonance Scattering on the Thermal Conductivity of ThO2
||Saqeeb Adnan, Zilong Hua, Amey Khanolkar, Cody Dennett, David Hurley, Marat Khafizov
|On-Site Speaker (Planned)
Understanding different phonon scattering mechanisms contributing to reduction of lattice thermal conductivity in fluorite oxides is critical to developing accurate fuel performance codes. In this study, we investigate low-temperature thermal conductivity in Uranium-doped and proton irradiated single-crystal ThO2(up to 0.1 dpa at 600C). Thermal conductivity of the hydrothermally grown samples was measured using spatial domain modulated thermoreflectance and was analyzed within the framework of Klemens-Callaway method. We observed that Umklapp scattering and Rayleigh scattering are insufficient to capture observed trends of thermal conductivity. Low-temperatures trends are reproduced by including an additional term associated with resonant scattering, which is characteristic of defects with peculiar electronic structures that enable coupling of certain phonon modes to either electronic degrees of freedom or localized phonon modes. While there are reports of phonon resonance in UO2, we notice that the analysis of proton-irradiated samples also requires the inclusion of resonant scattering associated with irradiation-induced defects.
||Nuclear Materials, Modeling and Simulation, Other