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RESEARCH PRODUCT
Crystallographic analysis of extended defects in diamond-type crystals
Sachiko T. NakagawaT. OnoHarry J. WhitlowHarry J. WhitlowGerhard BetzK. Ikusesubject
Nuclear and High Energy PhysicsMolecular dynamicschemistry.chemical_compoundCrystallographyDiamond typechemistryTetramerDimerAtomTrimerCrystalline siliconInstrumentationIondescription
Abstract To investigate irradiation-induced Si amorphization during its initial stages, we have performed a classical molecular-dynamics (MD) calculation for the case of self-irradiation by 5 keV ions at a low temperature of 100 K. We examined the geometry of self-interstitial atom (SIA) clusters using the pixel mapping (PM) method, on the output data of MD calculations. Perfect crystalline silicon (c-Si) is amorphized by self-irradiation, and we observe that many SIA are produced. During sequential self-irradiation, the most frequently observed species were isolated SIA, i.e. I1 (monomer). The fractions of SIA clusters decreased as I2 (dimer), I3 (trimer), and I4 (tetramer) clusters, respectively. For I2 clusters, the 〈1 1 0〉 oriented I2’s were the dominant I2 species, which agree with previous predictions based on static calculations. Nevertheless, other I2’s with different orientations were also significant. Some of them have been proposed as intermediate I2’s in forming dislocations. The present results imply that irradiation-induced SIA’s play an important role in the triggering of amorphization, and MD combined with PM can reveal the intermediate processes underlying extended-defect formation.
year | journal | country | edition | language |
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2005-05-01 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms |