| AVS 66th International Symposium & Exhibition | |
| Actinides and Rare Earths Focus Topic | Monday Sessions |
| Session AC-MoA |
| Session: | Early Career Scientists |
| Presenter: | Narayan Poudel, Idaho National Laboratory |
| Authors: | N. Poudel, Idaho National Laboratory X. Ding, Idaho National Laboratory J. Mann, Air Force Research Laboratory K. Gofryk, Idaho National Laboratory |
| Correspondent: | Click to Email |
Thorium dioxide (ThO2) crystalizes into CaF2-type (fluorite) cubic structure, similar to other members of AnO2 (An = Th-Am) family. Thorium dioxide forms stoichiometrically and is a wide-gap transparent insulator (Eg~5-6 eV). This material is used as nuclear fuel in certain types of nuclear reactors (CANDU) that might have more advantages than conventional UO2 based nuclear reactors. It is because of its higher thermal conductivity, higher corrosion resistance, and higher melting point. Despite its importance in nuclear technology, the thermodynamic and thermal transport properties of ThO2 single crystals have not been studied extensively, especially at low temperatures where many different scattering mechanisms such as boundary, defects, and/or phonon-phonon dominate the heat transport. In this talk, we will present our recent measurements of the heat capacity and thermal conductivity of ThO2 single crystals, obtained from room temperature down to 2 K. Large and good quality single crystals of ThO2 have been synthesized by hydrothermal method for this study. We will also compare the result obtained on ThO2 to UO2, especially in the context of impact of 5f-electrons on thermodynamic and transport behavior in these materials.