High temperature neutron diffraction investigation of U3Si2
[1];
[2];
[2];
[2];
[3];
- Univ. of South Carolina, Columbia, SC (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Texas at San Antonio, TX (United States)
- Univ. of South Carolina, Columbia, SC (United States)
The U-Si system is actively undergoing studies due to its promise as a component of an accident tolerant nuclear fuel. In this work, the crystal structure of the U3Si2 compound in the U-Si system was investigated as a function of temperature from room temperature to 1298 K for a sample of approximately 42.02 at.% Si composition and 1373 K for a sample with approximately 42.10 at.% Si using high temperature time-of-flight neutron diffraction on the High-Pressure Preferred Orientation (HIPPO) diffractometer at Los Alamos Neutron Science Center (LANSCE). The simultaneous Rietveld refinement of five histograms from the five HIPPO detector backs (40°, 60°, 90°, 120°, and 145°) provided datasets for the lattice parameters, anisotropic atomic displacement parameters, and atomic positions as a function of temperature. To explore the possibility of a homogeneity range, two sample compositions were analyzed, a 40.02 at.% Si (near stoichiometric) and a potentially hyperstoichiometric (40.10 at.% Si) sample. While minor differences in the anisotropic atomic displacement parameters between the two samples were observed, over the entire investigated temperature range no additional phases were found indicative of a single phase sample and the ability of the U3Si2 compound to accommodate nonstoichiometry, suggesting that the U3Si2 compound is not a line compound confirming previous determinations. However, the differences observed in the average coefficient of linear thermal expansion identified between the two compositions warrant future investigation.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA); USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5); USNRC
- Grant/Contract Number:
- 89233218CNA000001; 89233218NCA000001
- OSTI ID:
- 1605126
- Alternate ID(s):
- OSTI ID: 1581685
- Report Number(s):
- LA-UR-19-27352; LA-UR-18-28584
- Journal Information:
- Materialia, Vol. 9, Issue C; ISSN 2589-1529
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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