| Autor: |
R.B. Greegor, William J. Weber |
| Rok vydání: |
1990 |
| Předmět: |
|
| Zdroj: |
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 46:160-164 |
| ISSN: |
0168-583X |
| DOI: |
10.1016/0168-583x(90)90690-v |
| Popis: |
The effects of alpha irradiation on the rare-earth silicate, Ca2Nd8(SiO4)6O2, was investigated by X-ray diffraction. X-ray absorption near-edge spectroscopy (XANES), and extended X-ray fine structure (EXAFS) techniques. Irradiation with alpha particles emitted isotropically from a 238PuO2 source to a cumulative dose of 2.25 × 1021alphas/m2 (0.36 dpa) produced measurable anisotropic lattice expansions, with no tendency toward the amorphization that was previously reported due to self-radiation damage in Cm-doped samples at similar displacement-damage (0.25 dpa) levels. The unit-cell volume expanded exponentially with dose to a value corresponding to 2.5% volume expansion at saturation. The fluorescence XANES data of irradiated and unirradiated surfaces indicate a rearrangement of the near-neighbor ions about Nd. The EXAFS results indicate an irradiation-induced increase in structural disorder that becomes readily apparent at distances of several coordination spheres away from Nd. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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