The structural modification of C 60 films induced by 300-keV Xe-ion irradiation was investigated.The irradiated C 60 films were analysed using Fourier transform infrared spectroscopy,the Raman scattering technique,ultraviolet/visible spectrophotometry and atomic force microscopy.The analysis results indicate that the Xe-ion irradiation induces polymerization and damage of the C 60 molecule and significantly modifies the surface morphology and the optical property of the C 60 films.The damage cross-section for the C 60 molecule was also evaluated.
The effects of 100 keV H-ion implantation on the structure of LiTaO3 crystal are investigated by Raman and UV/VIS/NIR spectroscopies.The implantation fluence is in the range from 1.0 × 10^(13) to 1.0 × 10^(17) H^(+)/cm^(2).The experimental results show the dependence of the crystal structure on ion fluence.It is found that the structural modification of the LiTaO3 crystal is due to two processes.One is H-ions occupying lithium vacancies (VLi),which is predominant at a fluence less than 1.0 × 10^(14) H^(+) /cm^(2).This process causes the reduction of negative charge centers in the crystal and relaxation of distortion in the local lattice structure.The other is the influence of defects created during implantation,which plays a dominant role gradually in the structural modification at a fluence larger than 1.0 × 10^(15) H^(+)/cm^(2).
Different mass percent polyacrylonitrile (PAN)-polyethylene oxide (PEO) gels were prepared and irradiated by an electron beam (EB) with energy of 1.0 MeV to the dose ranging from 13 kGy to 260 kGy.The gels were analysed by using Fourier transform infrared spectrum,gel fraction and ionic conductivity (IC) measurement.The results show that the gel is crosslinked by EB irradiation,the crosslinking degree rises with the increasing EB irradiation dose (ID) and the mass percents of both PAN and PEO contribute a lot to the crosslinking;in addition,EB irradiation can promote the IC of PAN-PEO gels.There exists an optimum irradiation dose,at which the IC can increase dramatically.The IC changes of the PAN-PEO gels along with ID are divided into three regions:IC rapidly increasing region,IC decreasing region and IC balanced region.The cause of the change can be ascribed to two aspects,gel capturing electron degree and crosslinking degree.By comparing the IC-ID curves of different mass percents of PAN and PEO in gel,we found that PAN plays a more important role for gel IC promotion than PEO,since addition of PAN in gel causes the IC-ID curve sharper,while addition of PEO in gel causes the curve milder.
China reduced-activation ferritic/martensitic steel is irradiated at 773 K with 792 MeV Ar-ions to fluences of 2.3×10 20 and 4.6×10 20 ions/m2 , respectively. The variation of the microstructures of the Reduced-activation ferritic/martensitic (RAFM) steel samples with the Ar-ion penetration depth is investigated using a transmission electron microscope (TEM). From analyses of the microstructure changes along with the Ar-ions penetrating depth, it is found that high-density cavities form in the peak damage region. The average size and the number density of the cavities depend strongly on the damage level and Ar-atom concentration. Swelling due to the formation of cavities increases significantly with an increased damage level, and the existence of deposited Ar-atoms also enhances the growth of the average size of the cavities. The effect of atom displacements and Ar-atoms on the swelling of the RAFM steel under high energy Ar-ion irradiation is discussed briefly.
Austenitic stainless steels are a class structural material applied in current nuclear reactors and spallation targetsas well as future nuclear devices. It is well known, the migration and interaction of defects and their clusters andsmall dislocation loops caused by irradiation induce changes in mechanical properties of materials and result inradiation hardening and ductility loss of materials. In the present study, microstructure evolution in EC316LNaustenitic steel irradiated with mixed spectra of high-energy proton and spallation neutrons has been investigatedby using Transmission Electron Microscopy (TEM).
