| Autor: |
A.U. Kurkin, A.A. Schepetkin, O.V. Semenov, A. Ya. Kupryazhkin |
| Rok vydání: |
1994 |
| Předmět: |
|
| Zdroj: |
Journal of Nuclear Materials. 208:180-185 |
| ISSN: |
0022-3115 |
| Popis: |
Results on He solubility and diffusion and the influence of He on defect properties of CaF 2 , SrF 2 and BaF 2 are reported. A method of extracting the different diffusion paths using thermodesorption data has been developed and high- and low-rate mechanisms of He transport in CaF 2 have been observed. The interaction energy of He with crystals is − 0.4 eV for alkaline and − 0.5 eV for alkaline earth metal fluorides. The He interaction with fluoride ions is mainly repulsive. Low values of the dissolution energy are attributed to the attractive interaction of He with cations with interaction energies of − 0.5 eV for alkaline and − 0.7 eV for alkaline earth metals. Some data indicate strong He-induced stabilization of defects in CaF 2 and changes in thermostimulated luminescence characteristics of He-doped crystals. He stimulates the structural conversion of the tetragonal lattice of zirconium hydrides into the cubic modification. The experimental results provide evidence for the chemical bonds formed by He in the crystals. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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