Nonlinear Coefficient Determination of Au/Pd Bimetallic Nanoparticles Using Z-Scan

Abstract

In this paper we present the nonlinear optical characterization of Au/Pd nanoparticles in order to obtain the nonlinear refractive indices using the Z-scan technique. The experiments were performed using a 514 nm laser beam Ar + , with 14 Hz of modulation frequency, as excitation source. By using a lens the excitation beam was focused to a small spot and the sample was moved across the focal region along the z-axis by a motorized translation stage. Seven samples with different concentration ratio of Au/Pd nanoparticles were prepared by simultaneous reduction of gold and palladium ions in presence of poly (N-vinyl-2-pirrolidone) (PVP) using ethanol as a reducing agent. In this work, we report the application of the Z-scan technique, to generate optical transmission of laser light as a function of the z position for solutions containing bimetallic nanoparticles of Au (core)/Pd (shell) with average sizes ranging from 3 to 5 nm. The magnitude of the obtained nonlinear refractive index was in the order of 10 −8 cm 2 /W. Our results show that the nonlinear refractive index has a nonlinear behavior when the (Au/Pd) ratio was increased.

Hollow ZnO microspheres self-assembled from rod-like nanostructures: morphology-dependent linear and Kerr-type nonlinear optical properties

“…In addition, the difference between the peak and valley transmittances (DT PV ) in the absence of nonlinear absorption can be written in terms of the third-order nonlinear refraction (n 2 ) as DT PV ¼ 0:406ð1 À [68], where S ¼ 0:34 is the aperture transmittance, k is the irradiated beam wavelength and I 0 is the laser beam intensity at the focus. L eff is the effective length of sample which can be determined by using L eff ¼ 1ÀexpðÀa 0 LÞ a 0 equation [69]. L stands for the sample thickness while a 0 is the linear absorption coefficient.…”

Facile synthesis of ZnS–Ag2S core–shell nanospheres with enhanced nonlinear refraction

“…where ΔT PV = T P − T V stands for the transmittance difference between the peak and valley when T P and T V are considered as the normalized peak and valley transmittances, respectively. I 0 = 1.25 × 10 7 W∕m 2 refers to the incident intensity of laser beam at the focus and L eff is the effective length of the sample and is determined as follows [24]:…”

Spinodal Decomposition in Nanoparticles - Experiments and Simulation

“…One-and two-phase bimetallic nanoparticles are of great interest due to their good properties for a wide range of use. These cover chemical [1,2], catalytic [3], optical [4], biological [5] and plasmonic [6] applications as well. To prepare bimetallic nanoparticles co-deposition opens the possibility for mixing other ways immiscible components.…”