Radiation response of FeTiO3, MgTiO3, and α-Al2O3

The radiation response of three rhombohedral oxides, namely, ilmenite (FeTiO3), geikielite (MgTiO3), and sapphire (α-Al2O3) has been examined by irradiating electron transparent samples with 1 MeV Kr+and 1.5 MeV Xe+ ions. The microstructural changes during irradiation were observed in situ in a high-voltage electron microscope using electron diffraction and microscopy. The irradiation conditions were designed to minimize beam heating and chemical effects due to the implanted ion. In all three materials, the critical temperature for amorphization was below 300 K indicating good room temperature resistance to amorphization by energetic beams. The resistance to amorphization was found to increase with the melting point of the oxide—sapphire was the most resistant and ilmenite the least resistant to amorphization.