Formation and characterization of nanoparticles formed by sequential ion implantation of Au and Co into SiO2

Abstract

Nanoparticles (NPs) were formed by sequential ion implantation of Au and Co into thin SiO 2 . After Au implantation and annealing, Co implantations were carried out at room temperature (RT) and 400°C, respectively, with no subsequent annealing. The NPs were investigated by means of Rutherford backscattering spectroscopy (RBS), transmission electron microscopy (TEM) and extended Xray absorption fine structure spectroscopy (EXAFS). TEM shows the formation of Co-Au core-shell NPs for the Co implantation at 400°C. EXAFS measurements indicate significant strain in the NPs and a bond-length expansion of the Co-Co bonds in the NP core with a concomitant contraction of the Au-Au bonds in the Au shells. NPs are also observed by TEM for the Co implantation performed at RT, however, a lack of crystallinity is apparent from electron diffraction and EXAFS measurements.

Fabrication and thermal evolution of nanoparticles in SiO2 by Zn ion implantation

“…So far, many metal NPs and metal-oxide NPs, such as Cu, Au, Ni, NiO, Ag, Co, etc., have been synthesized in SiO 2 and Al 2 O 3 by means of ion implantation [9][10][11]. Especially, several groups reported that Zn and ZnO NPs have been fabricated in SiO 2 by ion implantation because of their possible applications in highperformance optoelectronics [12,13].…”