Amorphization of sapphire induced by swift heavy ions: A two step process

Structural disorder in sapphire induced by 90.3MeV xenon ions

“…1 (taken from [15]) presents the backscattering spectra of 2 MeV 4 He + ions from sapphire crystals irradiated with several fluences of 90.3 MeV xenon ions. At the opposite of the aluminium sublattice, only one disorder regime could be observed for the oxygen sublattice, and no highly disordered layer appears.…”

“…The minimum yields v min were 6.8% in the aluminium sublattice [15] and 17.4% in the oxygen sublattice.…”

“…In our previous work [15], we have evidenced, from RBS-C analysis of the aluminium sublattice, the presence of two incident xenon ions effects in sapphire: a partial disorder creation that saturates at $40% followed by a highly disordered layer developing from the surface to the depth above a threshold fluence of $1.2 Â 10 13 ions/cm 2 . But, for the oxygen sublattice, we observed only one effect that is the partial disorder creation.…”

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a b s t r a c tIn our previous work [15], we have evidenced, using RBS-C, two effects in the aluminium sublattice of sapphire irradiated with 90.3 MeV xenon ions: a partial disorder creation that saturates at $40% followed above a threshold fluence by a highly disordered layer appearing behind the surface. In this work, by RBS-C analysis of the oxygen sublattice, we have observed only one regime of partial disorder creation that saturates at $60% in tracks of cross-section double of that found for the aluminium sublattice.

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“…However, it presents an identical behaviour to that of non-amorphizable materials. That is why the microstructural changes induced in this material by ion irradiation in the electronic energy loss regime have been wildly studied [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”