Elektronenmikroskopische beobachtung von fehlstellenagglomeraten in kupfer nach beschuβ mit 5 keV argonionen

Abstract

ELECTRONMICROSCOPYSTUDYOFDEFECTSINCOPPERAFTER5 keVARGON IRRADIATION Foils of copper were bombarded with 5 keV argon ions with doses between 10¹¹ and 3 × 10¹¹ Ar⁺ cm⁻¹ (room temperature) and were investigated by transmission electron microscopy. For ion doses ≲10¹⁴ Ar⁺ cm⁻3, agglomerates of vacancies were found near the bombarded surfaco. These agglomerates were formed from the vacancy–rich region of displacement cascades initiated by the incoming ions. For doses ≲2 × 10¹⁵ Ar⁺ cm⁻², gas bubbles were observed in the same depth region. The bubbles were formed by the agglomeration of vacancies and argon atoms. Focusing collision sequences which originate from the cascades help interstitial atoms penetrate to greater depths in the lattice. The interatitials form visible agglomerates for doses ≲2× 10^{14 Ar}+ cm⁻². A complete model on the formation and visibility of the different defect agglomerates is deduced from the results.