Shape manipulation of ion irradiated Ag nanoparticles embedded in lithium niobate

Abstract

Spherical silver nanoparticles were prepared by means of ion beam synthesis in lithium niobate. The embedded nanoparticles were then irradiated with energetic (84)Kr and (197)Au ions, resulting in different electronic energy losses between 8.1 and 27.5 keV nm(-1) in the top layer of the samples. Due to the high electronic energy losses of the irradiating ions, molten ion tracks are formed inside the lithium niobate in which the elongated Ag nanoparticles are formed. This process is strongly dependent on the initial particle size and leads to a broad aspect ratio distribution. Extinction spectra of the samples feature the extinction maximum with shoulders on either side. While the maximum is caused by numerous remaining spherical nanoparticles, the shoulders can be attributed to elongated particles. The latter could be verified by COMSOL simulations. The extinction spectra are thus a superposition of the spectra of all individual particles.

Understanding the ion-induced elongation of silver nanoparticles embedded in silica

“…For instance, elongation of metallic nanoparticles using SHIs has been reported for cobalt NPs implanted in SiO 2 and irradiated with iodine 31 , for gold NPs implanted in planar SiO 2 films after irradiation with Si 32 and Cu 33 ions and Pt NPs formed by ion-beam synthesis in amorphous SiO 2 irradiated with Au ions 34 . More recently, there are also several works reporting the use of swift heavy ions to elongate Ag 35, 36 , Au 37–40 , Zn 41, 42 , and Ni 43 nanoparticles.…”

Plasmonic Nanoparticles in Dielectrics Synthesized by Ion Beams: Optical Properties and Photonic Applications

“…It is believed that the realization of elongation requires several basic conditions as follows: the high enough energy (hundreds of MeV) and proper fluence (≈10 13 ions cm −2 ) of implanted ions to form the ion tracks in the dielectrics; the larger diameter of NPs than the width of tracks (usually larger than 10 nm); and the suitable dielectrics. [ 90–102 ] It should be noted that the size condition of NPs for elongation is still under debate; and some experimental and theoretical studies on smaller NPs for effective elongation have been reported. [ 81 ] In this way, the NP–dielectrics systems can be well designed with tunable physical properties by optimizing the parameters during ion beam processing.…”

Near-infrared emission in Er:ZnO thin films with embedded Si nanoparticles synthesized by ion implantation

“…The direct implantation of Si ions can be used to synthesize NPs with spherical geometries in dielectrics. By the use of swift heavy ion irradiation, the nanostructures can be reshaped, thus elongating the spherical NPs in the thin films [12][13][14][15]. The concentration of NPs can be controlled by the ion dose.…”