Physical and optical properties of Cu nanoclusters fabricated by ion implantation in fused silica

Abstract

Cu clusters of nanometer dimensions were created by implantation of Cu ions into pure fused silica substrates at energies of 160 keV. The sizes and size distributions of the Cu clusters were measured by transmission electron microscopy, and were found to be determined by the ion-beam current during implantation. Optical-absorption spectra of these materials show the size-dependent surface plasmon resonance characteristic of noble-metal clusters. There are also significant size-dependent effects in both the nonlinear index of refraction and two-photon absorption coefficients. The distinctive variations in linear and nonlinear optical properties with Cu nanocluster sizes and size distributions affords potentially interesting possibilities for using these materials in nonlinear optical devices.

Competing processes during the production of metal nanoparticles by pulsed laser deposition

“…cm −2 ͒ in the implanted layer are, respectively, at least two orders and one order of magnitude smaller than those typically used for producing NPs by energetic ion implantation. 2,3 For the case of Cu, it has been reported that there is a critical dose for forming NPs, with this threshold being lower for low ion energy. 25 Although this agrees with our observations, the kinetic energies ͑25 keV and 3 MeV͒ for which this effect has been observed are still much higher than those involved in PLD.…”

“…This is typically in the range 10 13 -10 15 ions cm −2 s −1 for ion implantation. 2,3 It has recently been shown that for Ti implantation at 9 keV and a total dose of 6 ϫ 10 16 ions cm −2 , a decrease of the flux by a factor of two causes the metal to form a quasi-continuous layer rather than NPs. 24 PLD is a transient process since most of the deposition occurs during a period of several microseconds after the laser pulse, with this deposition being repeated after a pause of some hundred milliseconds at a typical laser pulse frequency of 10 Hz.…”

“…Common methods to produce NPs with controlled features are energetic ion implantation [1][2][3] or thin film technologies. [4][5][6] Whereas the former introduces the metal into a bulk dielectric, the latter produces both the metal NPs and the host using the same deposition technique.…”

Linear and Nonlinear Optical Properties of Metal Nanocluster-Silica Composites Formed by Sequential Implantation of Ag And Cu

“…While some of the broad absorption exhibited by the 9/3 Ag/Cu sample on the long wavelength side of the spectrum may be due to the small number of larger particles formed, all the absorption spectra appear to be dominated by the more numerous small particles whose sizes are more nearly represented by the mean particle size. 6 We conclude, based on the small differences in average particle size and the similar frequency of occurrence of the dominant particle sizes in all samples, that the changes observed in the linear optical spectra are due for the most part to interaction of the sequentially implanted ions to form metastable phases of varying concentrations of Ag and Cu. The compositions formed depend on the relative amounts of Ag and Cu sequentially implanted.…”

Gold nanoparticle assemblies: interplay between thermal effects and optical response

“…Liao et al have also invoked thermal effects to explain the discrepancies observed between different pulse temporal regimes [103]. Furthermore, several authors have demonstrated the involvement of thermal lens in the value of (3) χ , stemming from cumulative thermal effects generated at high pulse repetition rates [104][105][106][107]. We are thus led to define the thermo-optical contribution to the nonlinear refraction and absorption coefficients, th γ and th β .…”