Depth-resolved thermal conductivity and damage in swift heavy ion irradiated metal oxides
- Nazarbayev University, Nur-Sultan (Kazakhstan)
- Ohio State University, Columbus, OH (United States)
- Nelson Mandela University, Port Elizabeth (South Africa)
- Joint Institute for Nuclear Research, Moscow (Russia); National Research Nuclear University MEPhI, Moscow (Russia); Dubna State University, Moscow (Russia)
We investigated thermal transport in swift heavy ion (SHI) irradiated insulating single crystalline oxide materials: yttrium aluminum garnet- Y3Al5O12 (YAG), sapphire (Al2O3), zinc oxide (ZnO) and magnesium oxide (MgO) irradiated by 167 MeV Xe ions at 1012 – 1014 ions/cm2 fluences. Depth profiling of the thermal transport on nano- and micro- meter scales was assessed by time-domain thermoreflectance (TDTR) and modulated thermoreflectance (MTR) methods, respectively. This combination allowed us to isolate the conductivities of different sub-surface damage-regions characterized by their distinct microstructure evolution regimes. Thermal conductivity degradation in SHI irradiated YAG and Al2O3 is attributed to formation of ion tracks and subsequent amorphization, while in ZnO and MgO it is mostly due to point defects. Additionally, notably lower conductivity when probed by very low penetrating thermal waves is consistent with surface hillock formation. An analytical model based on Klemens-Callaway method for thermal conductivity coupled with a simplified microstructure evolution capturing saturation in defect concentration was used to obtain depth dependent damage across the ion impacted region. The studies showed that YAG has the highest damage profile resulting in the less dependence of thermal conductivity with the depth, while MgO on the contrary has the strongest dependence. The presented work sheds new light on how SHI induced defects affect thermal transport degradation and recovery of oxide ceramics as promising candidates for next generation nuclear reactor applications.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Thermal Energy Transport under Irradiation (TETI)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1981683
- Journal Information:
- Journal of Nuclear Materials, Vol. 561, Issue C; ISSN 0022-3115
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermal conductivity measurements via time-domain thermoreflectance for the characterization of radiation induced damage
Impact of irradiation induced dislocation loops on thermal conductivity in ceramics