Radiation defect dynamics studied by pulsed ion beams

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:409

Article; Proceedings Paper

Wallace, J. B.^1,2  Aji, L. B. Bayu¹  Shao, L.²  Kucheyev, S. O.¹ 

[1] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA

[2] Texas A&M Univ, Dept Nucl Engn, College Stn, TX 77843 USA

关键词: Radiation defects;    Dynamics;    Ion channeling;    Damage buildup;    Si;   

DOI  :  10.1016/j.nimb.2017.03.046

来源: Elsevier

【 摘 要 】

The formation of stable radiation damage in solids often proceeds via complex dynamic annealing processes, involving migration and interaction of ballistically-generated point defects. Our current understanding of the underlying physics is still not sufficient for predicting radiation damage even for Si, which is arguably the simplest and most extensively studied material. The complexity of radiation damage is closely related to radiation defect dynamics. Here, we demonstrate how defect interaction dynamics can be studied by pulsed beam irradiation when the total ion fluence is split into a train of equal square pulses. By varying the passive portion of the beam duty cycle, we measure a characteristic time constant of dynamic annealing and, hence, the defect relaxation rate. Measurements of stable lattice disorder as a function of the active portion of the beam duty cycle give an effective defect diffusion length. We illustrate the pulsed beam method with examples for Si bombarded at 100 degrees C with 500 keV Ar ions. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

Free