Annealing behavior of Ag nanoparticles in silica with and without defects

In this paper we investigated the annealing behavior of Ag nanoparticles in silica with and without defects. Silica samples with and without Ar ion pre-irradiation were implanted with Ag ions and then annealed at temperature from 300 to 850 °C. UV-VIS spectroscopy and TEM were used to characterize the optical absorbance property and size distribution of Ag nanoparticles, respectively. Optical absorbance results showed that the absorbance intensity of SPR peak from Ag nanoparticles in the sample with pre-irradiation was stronger than in the sample without pre-irradiation. During annealing, compared to the sample without pre-irradiation, the normalized absorbance intensity of SPR peak fluctuated in a smaller range with temperature for the sample with pre-irradiation. This indicated that defects produced by pre-irradiation prevented Ag nanoparticles from a rapid growth during annealing, namely had a stabilizing effect on Ag nanoparticles. However, in contrast to the sample without pre-irradiation, the SPR peak started to became broad and weak at a relative low temperature and fully disappeared after annealing at 850 °C for the sample with pre-irradiation. This indicated that defects could accelerate the decomposition of Ag nanoparticles at higher temperature.