Structural Distortion and Defects in Ti_3AlC_2 irradiated by Fe and He Ions

Ti_3AlC_2 samples are irradiated in advance by 3.5 MeV Fe-ion to the fluence of 1.0\times10^16 ion/cm^2, and then are implanted by 500 keV He-ion with the fluence of 1.0\times10^17 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.