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 cm2/W. Our results show that the nonlinear refractive index has a nonlinear behavior when the (Au/Pd) ratio was increased.
Highlights
Bimetallic nanoparticles (NPs) have attracted great interest among the scientific and technological community since they lead to many interesting size dependent electrical, chemical, and optical properties [1,2,3]
In order to obtain the aqueous nanofluids containing Au/Pd bimetallic nanoparticles, the colloidal dispersions were subsequently dried in vacuum and the metallic particles were dissolved in water maintaining the same initial concentrations of metal content and were placed in a quartz cuvette of 1 mm thick for the optical and thermal optical measurements
The nonlinearity properties of Au/Pd nanofluid prepared at different concentrations have been successfully investigated using a single beam Z-scan method
Summary
Bimetallic nanoparticles (NPs) have attracted great interest among the scientific and technological community since they lead to many interesting size dependent electrical, chemical, and optical properties [1,2,3]. They often exhibit enhanced catalytic properties which differ from that of their monometallic counterparts, in thin films [4]. Z-scan technique is one of the simplest and effective tools for measuring third order of nonlinear optics such as nonlinear refraction coefficient and absorption. It has been widely used in material characterization [17,18]. The converging and diverging of the beam (allowing more and less of the beam to pass through the aperture, respectively) due ANP
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
