About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Phase Transformations in Ceramics: Science and Applications
|
| Presentation Title |
Influence of Compositional Complexity on Transformations in Pyrochlore Oxides Under Highly Ionizing Radiation |
| Author(s) |
Kenneth Sanders, George Adamson, Cale Overstreet, Eric O'Quinn, Tao Liang, Haixuan Xu, Pascal Simon, Jesse Smith, Joerg Neuefeind, Joshua Safin, Katharine Page, Xing Wang, Blake Morgan, David Sprouster, Maik Lang |
| On-Site Speaker (Planned) |
Kenneth Sanders |
| Abstract Scope |
Compositionally complex ceramics offer desirable properties for numerous advanced technologies, including harsh environments like highly ionizing radiation conditions. The effects of compositional complexity on phase transformation behavior of pyrochlores under swift heavy ion irradiation were examined using 946 MeV Au ions at the GSI Helmholtz Centre. Subsequent characterization was performed using synchrotron-based X-ray scattering, neutron total scattering, high resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The amorphization behavior in compositionally complex titanate pyrochlores was comparable to that of conventional endmembers, exhibiting a mostly linear relationship between amorphous track core diameter and relative cation size. Density functional theory calculations of cation antisite defect energies confirmed a secondary non-linear effect, indicating that ‘medium entropy’ compounds may outperform complex compositions. An amorphous core / defective shell morphology is supported by HRTEM images of track cross-sections and X-ray diffraction measurements, which suggests epitaxial recrystallization occurs in a similar fashion to traditional pyrochlores. |