Study of Point Defect Distributions in Tantalum
A. Djaafria, A. Kadoun b, M. Driss-Khodja a, A. Elias a and T. Djaafri c
aLaboratoire d'Etudes Physico-Chimiques, Université Tahar Moulay, 20000 Saïda, Algeria
bLaboratoire de Microscopie, Microanalyse de la Matière et Spectroscopie Moléculaire, Université Djillali Liabes, 22000 Sidi-Bel-Abbes, Algeria
cDépartement de Physique, Université Tahar Moulay, 20000 Saïda, Algeria
Received: January 9, 2017; In final form: October 28, 2017
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We have investigated the point defect distributions in tantalum under irradiation by means of the Marlowe code based on the binary collision approximation. The study is carried out by simulating displacement cascades initiated with primary knock-on atom energies ranging from 5 to 20 keV. The Molière, Born-Mayer and average modified Lenz-Jensen potentials are used to describe the interactions between tantalum atoms. We have examined the creation of damage, the spatial defects distribution, and the vacancy clustering in tantalum. The results show that with an appropriate recombination radius, less than 16% of the created defects constitute permanent Frenkel pairs. Spatial configuration of defects indicates a separation between the two point defect types, vacancies and interstitials. The Molière potential favors the production of a greater number of displaced atoms and the development of voluminous cascades more than the other potentials. The cascade volume distributions deviate clearly from a Gaussian distribution. They are large and very stretched toward higher volumes for all used potentials. Only small vacancy clusters are formed in tantalum under irradiation and about 41% of the produced vacancies are considered as isolated

DOI: 10.12693/APhysPolA.133.39
PACS numbers: 61.82.Bg, 61.80.Ed, 61.72.jj, 61.72.jn