Fabrication of nickel oxide nanoparticles in SiO2 by metal-ion implantation combined with thermal oxidation

Abstract

A method is proposed to synthesize oxide nanoparticles in insulators, using metal-ion implantation and following thermal oxidation, which introduces less damage compared to the sequential implantation of metal ions and oxygen ions. Ni-oxide nanoparticles are formed in O2 gas flow at ∼800°C for 1h, through thermal oxidation of Ni metal nanoparticles, which were introduced in SiO2 by charging-free negative ion implantation of 60keV. After the oxidation, optical absorption in the visible region, which is due to Ni metal nanoparticles in the specimen, disappears, and a steep absorption edge of insulator NiO appears around ∼4eV. Simultaneously, the large magnetization of Ni metal nanoparticles changes to a weak magnetization of antiferromagnetic NiO nanoparticles. The nanoparticle formation is confirmed by transmission electron microscopy observation.

Zn and ZnO nanoparticles fabricated by ion implantation combined with thermal oxidation, and the defect-free luminescence

“…Shallowing of the depth profile of metal NPs induced in oxidizing atmosphere has been also observed in Fe in Al 2 O 3 11 and in Ge in SiO 2 . 12 Here, we apply the model which has been proposed in Ge 12 to our Zn case: With increasing temperature, a lot of Zn atoms are detached from Zn NPs, and migrate in SiO 2 toward both directions of the surface side and deeper side.…”

“…It is in contrast with NiO and CuO phases fabricated by the IICTO method, which are always obtained as NPs embedded in SiO 2 substrate. [3][4][5] Since Zn ions were implanted inside of the SiO 2 substrate, and since ZnO is formed on the surface of the SiO 2 substrate, drastic transportation of Zn element from inside of the SiO 2 substrate toward the surface is expected during the thermal oxidation. In this letter, cross-sectional transmission microscopy ͑XTEM͒ was applied at different annealing temperatures to confirm the drastic transportation of Zn atoms from inside of the SiO 2 substrate to the surface.…”

Formation processes of zinc-oxide nanoparticles by ion implantation combined with thermal oxidation

“…Up to now, we have fabricated metal-oxide nanoparticles (NPs), such as nickel-oxide (NiO) [3,4] and cupric-oxide (CuO) [5] in silica glasses (SiO 2 ) using metal-ion implantation and following thermal oxidation. In this study, the method is applied to fabrication of ZnO NPs in SiO 2 .…”

Sol–gel processing of a bimetallic alkoxide precursor confined in a porous glass matrix: A route to novel glass/metal oxide nanocomposites

“…Nanocomposite materials formed by oxide, semiconductor or metal nanoparticles embedded in glasses have attracted much attention due to the potential practical applications of these materials in fields as optics, catalysis and magnetism [1][2][3][4][5][6][7][8][9][10]. In the case of oxide-based nanocomposites, in particular iron or titanium oxides, the main interest lies in the excellent magnetic and catalytic properties of these materials [6][7][8][9][10][11][12][13][14].…”