Minghuan Cui

The study of damage produced by H-ion and He-ion implantation in Lithium tantalate crystal

LiTaO3 single crystals were implanted by 100keV H-ion or He-ion. The results indicate that H-ion implantation creates a lower damage level than the He-ion implantation does, but the yield of oxygen vacancy produced by H-ion implantation is far higher than by He-ion implantation.

Structural Distortion and Defects in Ti

Ti3AlC2 samples are irradiated in advance by 3.5MeV Fe-ion to the fluence of 1.0×10 16 ion/cm 2 , and then are implanted by 500 keV He-ion with the fluence of 1.0×10 17 ion/cm 2 at room temperature. The irradiated samples are investigated by grazing incidence x-ray diffraction (GIXRD) and transmission electron microscopy (TEM). GIXRD results show serious structural distortion, but without amorphization in the irradiated samples. Fe-ion irradiation and He-ion implantation create much more serious structural distortion than single Fe-ion irradiation. TEM results reveal that there are a large number of defect clusters in the damage region, and dense spherical He bubbles appear in the He depositional region. It seems that the pre-damage does not influence the growth of He bubbles, but He-ion implantation influences the pre-created defect configurations.

_{3}

A type of home-made reduced activation martensitic steel, high silicon (SIMP) steel, is homogeneously irradiated with energetic Fe ions to the doses of 0.1, 0.25 and 1 displacement per atom (dpa), respectively, at 300°C and 1 dpa, at 400°C. Microstructural changes are investigated in detail by transmission electron microscopy with cross-section technique. Interstitial defects and defect clusters induced by Fe-ion irradiation are observed in all the specimens under different conditions. It is found that with increasing irradiation temperature, size of defect clusters increases while the density drops quickly. The results of element chemical mapping from the STEM images indicate that the Si element enrichment and Ta element depletion occur inside the precipitates in the matrix of SIMP steel irradiated to a dose of 1 dpa at 300°C. Correlations between the microstructure and irradiation conditions are briefly discussed.

AlC

In this work, nano-hardness of the ferritic/martensitic (F/M) steel T91 caused by self-ion irradiation has been studied. The samples were irradiated with 3.25 MeV Fe13+ ions to different doses at different implantation temperatures. The results of nano-indentation measurement show that the hardness of the samples increases with irradiation dose and temperature.