Abstract
In situ synchrotron high-energy x-ray diffraction experiments and detailed transmission electron microscopy (TEM) characterization were conducted on as-fabricated and neutron-irradiated yttrium hydrides. The high-resolution synchrotron x-ray diffraction revealed minor α yttrium and major δ yttrium hydride phases in all specimens. Specimens were subject to heat treatments (heating-cooling cycles), and the intensity of α yttrium partially and completely disappeared in as-fabricated and neutron-irradiated specimens, respectively. The disappearance of α yttrium was unforeseen because hydrogen was expected to leave δ phase, causing an increase in α yttrium diffraction peak intensity. This observation indicated a surplus of hydrogen in the specimens where it was odd for hydride-forming early transition metal elements. The subsequent through-focus TEM characterization discovered nanometric cavities in both as-fabricated and neutron-irradiated yttrium hydride specimens for the first time. Two types of cavities were identified as fabrication-caused and irradiation-induced. The fabrication-caused cavities were associated with regions having linear deformation features, interfaces, and inclusions. The irradiation-induced cavities were observed as being formed isolated in the yttrium hydride phase. The presence of such nanometric cavities was considered as potential hydrogen storage pockets where the overall hydrogen storing capacity of yttrium hydride would be enhanced.
| Original language | English |
|---|---|
| Article number | 101933 |
| Journal | Materialia |
| Volume | 32 |
| DOIs | |
| State | Published - Dec 2023 |
Funding
This research used the x-ray powder diffraction beamline (28-ID-2) at the National Synchrotron Light Source II, a Department of Energy (DOE) Office of Science user facility operated for the DOE Office of Science by Brookhaven National Laboratory under contract no. DE-SC0012704 . The beamline work was supported by the U.S. DOE Office of Nuclear Energy under DOE Idaho Operations Office Contract DE-AC07- 05ID14517 as part of a Nuclear Science User Facilities experiment. Neutron-irradiated sample preparation work was supported by the U.S. DOE-NE's Advanced Materials and Manufacturing Technologies Program at Oak Ridge National Laboratory. Data analysis and manuscript preparation portion was supported by the Laboratory Directed Research and Development funding from Idaho National Laboratory , managed by Battelle Energy Alliance, LLC, under Contract No. DE-AC07 – 05ID14517 . This manuscript was authored by Battelle Energy Alliance, LLC, under Contract No. DE-AC07 – 05ID14517 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes. The authors thank Sanjit Ghose, Hui Zhong, Jianming Bai, and John Trunk at Brookhaven National Laboratory for their support during in-situ x-ray diffraction measurements. This research used the x-ray powder diffraction beamline (28-ID-2) at the National Synchrotron Light Source II, a Department of Energy (DOE) Office of Science user facility operated for the DOE Office of Science by Brookhaven National Laboratory under contract no. DE-SC0012704. The beamline work was supported by the U.S. DOE Office of Nuclear Energy under DOE Idaho Operations Office Contract DE-AC07- 05ID14517 as part of a Nuclear Science User Facilities experiment. Neutron-irradiated sample preparation work was supported by the U.S. DOE-NE's Advanced Materials and Manufacturing Technologies Program at Oak Ridge National Laboratory. Data analysis and manuscript preparation portion was supported by the Laboratory Directed Research and Development funding from Idaho National Laboratory, managed by Battelle Energy Alliance, LLC, under Contract No. DE-AC07–05ID14517. This manuscript was authored by Battelle Energy Alliance, LLC, under Contract No. DE-AC07–05ID14517 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes. The authors thank Sanjit Ghose, Hui Zhong, Jianming Bai, and John Trunk at Brookhaven National Laboratory for their support during in-situ x-ray diffraction measurements.
Keywords
- Hydrogen
- Irradiation-induced defects
- Metal hydrides
- Nanometric cavities
- Neutron irradiation
- Radiation-damage
- Synchrotron diffraction
- Transmission electron microscopy
- Yttrium hydride
