Heisenberg model for radical reactions. Part 3. Direct exchange coupling between transition metal ions and triplet methylene

1994 ◽  
Vol 310 ◽  
pp. 185-196 ◽  
Author(s):  
S. Yamanaka ◽  
T. Kawamura ◽  
T. Noro ◽  
K. Yamaguchi
2002 ◽  
Vol 124 (18) ◽  
pp. 5197-5205 ◽  
Author(s):  
Cédric Desplanches ◽  
Eliseo Ruiz ◽  
Antonio Rodríguez-Fortea ◽  
Santiago Alvarez

Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.


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