Positron States in Dislocations: Shallow and Deep Traps
1989; Institute of Physics; Volume: 9; Issue: 8 Linguagem: Inglês
10.1209/0295-5075/9/8/012
ISSN1286-4854
AutoresHannu Häkkinen, Seppo Mäkinen, M. Manninen,
Tópico(s)Atomic and Molecular Physics
ResumoStructures of edge dislocations in aluminum are calculated using molecular dynamics and an effective medium theory with many-atom interactions. The local density approximation is used to calculate the positron states at different trapping sites. The partial [211]-dislocation is a very shallow trap with a positron binding energy of less than 80 meV and a positron lifetime similar to the bulk lifetime. Vacancies and single jogs at the dislocation line result in a lifetime of about 224 ps which is in a good agreement with the experimentally observed lifetimes in aluminum containing dislocations.
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