Ion irradiation induced amorphization of SnO2 nanoparticles embedded in SiO2

SnO2 nanoparticles (NPs) of average diameter of ∼10.5 nm, synthesized in SiO2 using Sn− ions implantation combined with thermal annealing, were irradiated with 1.5 MeV Au2+ ions at room temperature. The NP structure was studied as a function of ion fluence by transmission electron microscopy and micro-Raman spectroscopy. Prior to ion irradiation, SnO2 NPs have been found to exhibit the rutile crystal structure. Upon irradiation, amorphization in the nanocrystals has been seen to increase with increase in ion fluence. In particular, at a fluence of 1 × 1014 ions cm−2 we argue for the presence of an amorphous SnO2 phase. Beyond this fluence, the NPs have been found to dissolve in the matrix. The observed results are explained in the frame work of ion irradiation induced defects production in the NPs as well as in the NP/matrix interface.