Fabrication Of TiO₂Nanoparticles And Ion Beam Irradiation Induced Modification Of Cu Nanoparticles In SiO₂Substrate

Owing to their peculiar properties, nanoparticles (NPs) have many potentialapplications in various fields, such as opto-electronics, biosensor, solar cell, opticalswitch etc. Nowadays, the fabrication and characterization of NPs have become oneof the most important research fields in nanoscience and technology. In this paper,NPs were synthesized by using ion implantation、heavy ion irradiation and subsequentthermal annealing. X-ray diffraction spectroscopy (XRD), ultra-violet-visible opticalspectroscopy (UV-Vis), Rutherford Backscattering Spectrometry (RBS) andcross-sectional transmission electron microscopy (TEM), were used to study themicrostructure、spatial distribution and optical property of NPs. The research contentsand corresponding results are given as follows:(1) SiO2samples were sequentially implanted with70keV Zn ion at a fluenec of1×1016/cm2and45keV Ti ion at fluence of5×1016and1×1017/cm2，and were thensubsequently furnace annealed in oxygen ambient from400to900oC. Our resultsclearly show that high quality TiO2NPs can be synthesized by increasing theimplanted Ti ion fluence. Pre-implanted Zn ions could affect the optical absorptionproperties by changing the spatial distribution of Ti ions and the dielectric aroundTiO2NPs. The Zn ions also could suppress the growth of TiO2NPs around them.(2) SiO2samples implanted with30keV Ti ions at a fluence of1×1017/cm2wereirradiated by100keV Xe ions at a fluence of1×1016/cm2, in order to change thespatial distribution、crystalline structure and optical absorption properties of Ti NPs.RBS results indicate that subsequent Xe ion irradiation leads to the broader spatialdistribution of Ti ions. The pure rutile TiO2NPs were synthesized and the absorptionedge red shifted after700oC annealing in oxygen ambient. As the temperature reachesat800oC，TiSiO4crystalline were detected in SiO2substrate, the absorption edgeshould be attributed to the role of both TiSiO4and rutile TiO2.(3) SiO2samples implanted with45keV Cu ions at a fluence of1×1017/cm2wereirradiated by500keV Ar and Xe ions, in order to tailor the size and spatialdistributions of the embedded Cu NPs along with their optical absorption property.The applied fluence for Ar ions was fixed at1×1016/cm2, while that for Xe ions wasin the range of1×1015~2×1016/cm2. The TEM results clearly show that after Xe ionirradiation at a fluence of2×1016/cm2, the larger Cu NPs uniformly aligned at the same depth beyond the projected range of Cu ions, and the average diameter of CuNPs was increased from7.3to8.5nm, which lead to the absorbance unitarilyincreased after500oC thermal annealing. Moreover, after Xe ion irradiation at thefluence of1×1015/cm2， the absorbance unitarily decreased after500oC thermalannealing. In additional, Xe ion irradiation was found to be more effective to modifythe Cu SPR peak thanAr ion irradiation with the same implantation condition.