Fabrication, Characterization And Modulation Of Nanoparticles In SiO₂Implanted With Ni、Ag Ions

In this dissertation, silica (SiO2) samples were implanted by60keV Ni ions and70keV Ag ions respectively and successively. The fabrication of nanoparticles (NPs), their thermal evolution as well as their optical absorption properties were studied through a series of analytical techniques, including ultraviolet and visible spectrophototometer (UV-Vis), atomic force microscope (AFM), Rutherford backscattering spectroscopy (RBS), and grazing incidence X-ray diffraction (GXRD). The main contents and results are given as follows:(1) SiO2samples were implanted by60keV Ni ions with the fluences of1×1016,5×1016and1×1017ions/cm2respectively. The formation of Ni NPs was systematically studied as a function of implanted fluence. Results showed that no nanoparticles (NPs) formed in the samples implanted by the fluence of1×1016/cm2; while Ni NPs were observed in the samples implanted by the fluences5×1016/cm2and1×1017/cm2respectively. After annealed in Ar, Ni NPs grew and the height of hillocks (Ni NPs) increased with a decrease in numbers. The weak optical absorption bands of Ni NPs were located at310nm to530nm of the spectra, and a buleshift appeared after800℃annealing. After1000℃, Ni NPs were oxidized into NiO whose absorption band located at about300nm.(2) SiO2samples were implanted by70keV Ag ions with the fluence of5×1016/cm2, and then annealed in different ambient (Ar, N2, air). The influences of ambient to the thermal evolution of Ag NPs were studied in detail. Ag atoms diffused into the depths when annealed in Ar, however, they moved towards the surface of SiO2when annealed in N2, and their distribution narrowed down. It showed the strongest optical absorption after annealed both in Ar and N2. When annealed in air, part of Ag atoms were oxidized to AgO, and that weakened the optical absorption. Crystallization temperature reduced as the resulted of doping of Ag ions, and the implanted samples started crystallizing when annealed at700℃,in air.(3) SiO2samples were implanted by60keV Ni ions and70keV Ag ions successively. The fluence of Ni ions were1×1016,5×1016and1×1017/cm2respectively, and Ag ions was5×1016/cm2. The influences of pre-implanted fluences of Ni ions was studied. Results showed that:optical absorption of Ni-Ag implanted samples was weaker than that implanted by Ag ions singly. SPR position blue shifted with the increasing fluence of Ni ions. SPR intensity did not change linearly with the increasing fluence of Ni ions.