Combination of RBS/C and Raman techniques for the investigation of the SNEEL phenomenon in ion-irradiated materials

(1) CSNSM, CNRS-IN2P3-Université Paris-Sud, F-91405 Orsay, France
(2) CEA, DMN/SRMP/Laboratoire JANNUS, F-91191 Gif/Yvette Cedex, France

Very recently, a new phenomenon called SNEEL (Synergy between Nuclear and Electronic Energy Losses) was discovered to take place in some solids irradiated with a dual low- and high-energy ion beam [1-2]. This process induces a strong decrease of the damage induced by ballistic collisions generated by slow ions (Sn) via self-healing mechanisms due to ionization from the electronic energy loss of swift ions (Se). This paper presents studies performed in order to make strides in the understanding of the SNEEL phenomenon occurring in SiC. The combination of RBS/C and Raman techniques were used to characterize the damage accumulated during the various irradiation steps. Results show that dual-beam irradiation of SiC induces a dramatic change in the final sample microstructure with a substantial decrease of radiation damage as compared to single-beam irradiation. Actually, a defective layer containing dislocations is formed upon dual-beam irradiation (Sn&Se), whereas single low-energy irradiation (Sn alone) or even sequential (Sn+Se) irradiations lead to full amorphization. The results presented in this paper present a crucial interest for both fundamental studies and industrial applications. Concerning the operating cycle of future nuclear reactors, expected synergetic Sn/Se effects may lead to a strong reduction of the damage production allowing the preservation of the physical integrity of materials submitted to severe irradiations.  

[1] L. Thomé et al, Appl. Phys. Lett. 102, 141906 (2013). [2]    L. Thomé et al, J. Appl. Phys. (2015) in press.