DEPTH-RESOLVED THERMAL CONDUCTIVITY AND DAMAGE IN SWIFT HEAVY ION IRRADIATED METAL OXIDES
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Date
2022
Authors
Abdullaev, Azat
Koshkinbayeva, Ainur
Chauhan, Vinay
Nurekeyev, Zhangatay
O’Connell, Jacques
van Vuuren, Arno Janse
Skuratov, Vladimir
Khafizov, Marat
Utegulov, Zhandos N.
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Nuclear Materials
Abstract
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 ther mal 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 for mation 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.
Description
Keywords
Type of access: Open Access, Thermal transport, Swift heavy ions, Amorphization Ion tracks, Phonon scattering, Metal oxides
Citation
Abdullaev, A., Koshkinbayeva, A., Chauhan, V., Nurekeyev, Z., O’Connell, J., van Vuuren, A. J., Skuratov, V., Khafizov, M., & Utegulov, Z. N. (2022). Depth-resolved thermal conductivity and damage in swift heavy ion irradiated metal oxides. Journal of Nuclear Materials, 561, 153563. https://doi.org/10.1016/j.jnucmat.2022.153563