Local structure and vibrational properties of alpha'-Pu martensitein Ga-stabilized delta-Pu
Extended x-ray absorption fine structure spectroscopy (EXAFS) is used to investigate the local atomic environment and vibrational properties of plutonium and gallium atoms in the {alpha}{prime} and {delta} phases of a mixed phase Pu-Ga alloy. EXAFS results measured at low temperature compare the structure of the mixed phase sample with a single-phase {delta}-Pu sample. EXAFS spectral components attributed to both {alpha}{prime}-Pu and {delta}-Pu were observed in the mixed phase sample. Ga K-edge EXAFS spectra indicate local atomic environments similar to the Pu LIII-edge EXAFS results, which suggests that Ga is substitutional for Pu atoms in both the monoclinic {alpha}{prime}-Pu and the fcc {delta}-Pu structures. In {delta}-Pu, we measure a Ga-Pu bond length contraction of 0.11 Angstroms with respect to the Pu-Pu bond length. The corresponding bond-length contraction around Ga in {alpha}{prime}-Pu is only 0.03 Angstroms. Results from temperature-dependent Pu LIII-edge EXAFS measurements are fit to a correlated Debye model, and a large difference in the Pu-Pu bond Debye temperature is observed for the {alpha}{prime} and {delta} phases: {theta}{sub cD}({alpha}{prime})=159{+-}13 K versus {theta}{sub cD}({delta})=120{+-}3 K. The corresponding analysis for the Ga K EXAFS determines a Ga-Pu bond Debye temperature of {theta}{sub cD}({delta})=188{+-}12 K in the {delta}-Pu phase. These results are related to the observed solubility of Ga in {delta}-Pu, the ''stabilization'' of {delta}-Pu by Ga at room temperature, and the insolubility of Ga in {alpha}{prime}-Pu.
- Research Organization:
- COLLABORATION - LLNL
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 917805
- Report Number(s):
- LBNL-52413; UCRL-JC-151541; PRBMDO; R&D Project: 403005; BnR: KC0302030; TRN: US0805121
- Journal Information:
- Physical Review B, Vol. 67, Issue 22; Related Information: Journal Publication Date: 11/11/2003; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
Similar Records
Local Structure and Vibrational Properties of alpha-Pu, alpha-U, and the alpha-U Charge Density Wave
Local structure and vibrational properties of {alpha}-Pu, {alpha}-U, and the {alpha}-U charge-density wave