It was recalled that this material was considered to be radiation-resistant. Here, the spinel was bombarded with 1.5MeV Kr+ at 20K and was studied by means of  in situ transmission electron microscopy. It was found that the spinel remained crystalline up to a dose of 1016/cm2, with no sign of amorphization. Another sample was pre-implanted (50 or 400keV Ne) and the microstructure again remained crystalline, with 8nm interstitial loops. After irradiation with 1.5MeV Kr+ (20K), an amorphization which was the result of cation disordering began at a dose of 1.7 x 1015/cm2. After a dose of 1016/cm2, the spinel was partially amorphous while the remaining crystalline domains were disordered. The results showed that the spinel could be disordered, and that amorphization could be triggered by the introduction of stable defects; followed by low-temperature ion bombardment.

N.Bordes, L.M.Wang, R.C.Ewing, K.E.Sickafus: Journal of Materials Research, 1995, 10[4], 981-5