Polycrystalline Al2O3, magnesium aluminate spinel (MgAl2O4), MgO, Si3N4, and SiC were irradiated with various ions at 200-450 K, and microstructures were examined following irradiation using cross-section TEM. Amorphization was not observed in any of the irradiated oxide ceramics, despsite damage energy densities up to {similar_to}7 keV/atom (70 displacements per atom). On the other hand, SiC readily amorphized after damage levels of {similar_to}0.4 dpa at room temperature (RT). Si3N4 exhibited intermediate behavior; irradiation with Fe{sup 2+} ions at RT produced amorphization in the implanted ion region after damage levels of {similar_to}1 dpa. However, irradiated regions outside the implanted ion region did not amorphize even after damage levels > 5 dpa. The amorphous layer in the Fe-implanted region of Si3N4 did not appear if the specimen was simultaneoulsy irradiated with 1-MeV He{sup +} ions at RT. By comparison with published results, it is concluded that the implantation of certain chemical species has a pronounced effect on the amorphization threshold dose of all five materials. Intense ionizing radiation inhibits amorphization in Si3N4, but does not appear to significantly influence the amorphization of SiC.

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Influence of irradiation spectrum and implanted ions on the amorphization of ceramics

Microstructural evolution of helium-irradiated 6H–SiC subjected to different irradiation conditions and annealing temperatures: A multiple characterization study

The structural evolution of light-ion implanted 6H-SiC single crystal: Comparison of the effect of helium and hydrogen

Effects of displacement damage and helium production rates on the nucleation and growth of helium bubbles – Positron annihilation spectroscopy aspects

6H-SiC blistering efficiency as a function of the hydrogen implantation fluence

Study of the damage produced in 6H-SiC by He irradiation

Transmission electron microscopy investigations of bubble formation in He-implanted polycrystalline SiC

Solid phase epitaxial growth of amorphous 6H-SiC created by 15 keV He ion implantation to doses of 15 × 10 16 , 5 × 10 16 and 1 × 10 17  cm −2 at room temperature (RT) followed by annealing ranging from 600 °C to 900 °C for 30 min was investigated The recrystallization process was investigated via cross-sectional transmission electron microscopy (XTEM) Recrystallization initially nucleates and grows at the interface between the amorphous layer and 6H-SiC substrate In the middle of the amorphous layer, recrystallization nucleation is inhibited Recrystallization rate is related to the implantation-induced damage and concentration of He impurity The Fourier transformed images denote that the region of recrystallization contains 3C-SiC and 6H-SiC with different crystalline orientations Besides, for the 1 × 10 17  cm − 2 implanted sample, partial areas are kept amorphous in the damaged layer The threshold temperature of full recrystallization of He ion-implantation-induced amorphization in 6H-SiC and the previous observations on other ions implantation, such as Ne, Ar, Xe etc is compared The possible reasons are discussed

B.S. Li

Papers

6H-SiC blistering efficiency as a function of the hydrogen implantation fluence

Study of the damage produced in 6H-SiC by He irradiation

Transmission electron microscopy investigations of bubble formation in He-implanted polycrystalline SiC

Recrystallization of He-ion implanted 6H-SiC upon annealing

Study of surface blistering in GaN by hydrogen implantation at elevated temperatures