Zur thermischen Ausheilung von Kernrückstoßdefekten in neutronenbestrahlten, kristallinen Ir(IV)- und Os(IV)-Hexahalogen-Komplexen
Zur thermischen Ausheilung von Kernrückstoßdefekten in neutronenbestrahlten, kristallinen Ir(IV)- und Os(IV)-Hexahalogen-Komplexen
The S$_{ZILARD}-C_{HALMERS}$ process of ligand and central atoms in neutron irradiated $Na_{2}IrCl_{6}$ • 6 H$_{2}$O, K$_{2}IrBr_{6}$ , K$_{2}OsBr_{6}$ and (NH$_{4}$) $_{2}OsBr_{6}$ has been investigated in some detail. Whereas in Na$_{2}IrCl_{6}$ • 6 H$_{2}$O seven $^{192}$Ir-recoil species are for...
Saved in:
Personal Name(s): | Herr, W. |
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Heine, K. / Schmidt, G. B. | |
Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Kernforschungsanlage Jülich, Verlag
1962
|
Physical Description: |
p. 590-6 |
Document Type: |
Report Book |
Research Program: |
Addenda |
Series Title: |
Berichte der Kernforschungsanlage Jülich
86 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
The S$_{ZILARD}-C_{HALMERS}$ process of ligand and central atoms in neutron irradiated $Na_{2}IrCl_{6}$ • 6 H$_{2}$O, K$_{2}IrBr_{6}$ , K$_{2}OsBr_{6}$ and (NH$_{4}$) $_{2}OsBr_{6}$ has been investigated in some detail. Whereas in Na$_{2}IrCl_{6}$ • 6 H$_{2}$O seven $^{192}$Ir-recoil species are formed, which show an individual annealing behaviour, recoil $^{82}$Br has been observed only in the chemical forms of Br$^{-}$ and the original hexabromocomplexes. The retention of the $^{192}$Ir central atom is only 3% in Na$_{2}IrCl_{6}$ · 6 H$_{2}$O and 38% in K$_{2}IrBr_{6}$. In contrast, we observed 80-90% $^{82}$Br-retention (R$_{0}$) of the ligand atom. These high R$_{0}$-values indicate an instantaneous annealing reaction, which might be explained by a billiard-ball mechanism and/or by activated exchange reactions. The thermal annealing of $_{82}$Br approaches a retention value of 100% quickly at high temperatures ($\thicksim$ 200 °C) or for long heating tim es. The kinetics of $^{192}$Ir and $^{82}$Br annealing are discussed. For the fast annealing process of recoil-$^{82}$Br an activation energy of about3-4 kcal/mol was calculated. The results show, that physical models alone do not explain the annealing behaviour of the recoils satisfactorily. We must therefore assume, that also chemical reactions are important. |