This paper develops a novel method for simultaneously determining the plasma frequency ωP and damping constant γfree in bulk damped oscillator Drude model, based on experimentally measured real imaginary parts of metal refractive index IR wavelength range, lifting usual approximation that restricts values to UV-deep UV region. Our was applied gold, silver, copper, improving relative uncertainties final ωp (0.5%–1.6%) (3%–8%), which are smaller than those reported literature. These small...

Nanoparticles find applications in multiple technological and scientific fields, laser ablation liquid (LAL) emerged as a versatile method for providing colloidal solutions of nanomaterials with various composition, by low cost, simple, self-standing, "green" procedure. However, the use high energy power beams is harmful, especially when coupled flammable or toxic liquids, situ operation required starting, monitoring LAL synthesis, stopping it at desired point. Here we describe hardware...

We report on the analysis of structure, configuration, and sizing Cu oxide nanoparticles (Nps) produced by femtosecond (fs) laser ablation solid copper target in liquids. Laser pulse energy ranged between 500 μJ 50 μJ. Water acetone were used to produce colloidal suspensions. The study was performed through optical extinction spectroscopy using Mie theory fit full experimental spectra, considering free bound electrons size dependent contributions metal dielectric function. Raman AFM...

Synthesis of nickel (Ni) nanoparticles (NPs) suspensions was performed using a 120 fs (femtosecond) pulse laser to ablate Ni solid target in n-heptane and water. Analysis structure, configuration, sizing carried out different independent techniques, such as optical extinction spectroscopy (OES), atomic force microscopy (AFM), transmission electron (TEM), diffraction (ED), which yield interrelated information. AFM allows determining the spherical shape size distribution NPs obtained colloids,...

Abstract While there are conventional chemical synthesis methods to generate metal nanoclusters (NCs), many of them adversely affected by the unavoidable contamination nanoproduct solution, resulting in aggregation, background noise analytical chemistry, toxicity, and deactivation catalyst. In this work, physical method ultrafast laser ablation as a “green” approach together with mechanical centrifugation obtain silver NCs, simplifying widely requirements, is proposed. Remarkably, compared...

The generation of small silver metal nanoparticles (Nps) by ultrashort pulsed laser ablation has been an active area research in recent years due to their interest several fields applied such as biotechnology and material research, particular those with sizes smaller than 10 nm. In general, tends produce environmentally clean Nps compared wet chemical methods. However, since may be oxidized the presence water or ethanol, core–shell silver–silver oxide (Ag–Ag2O) can formed, whose size...

Abstract Magnetic nanoparticles have attracted much interest due to their broad applications in biomedicine and pollutant remediation. In this work, the optical, magnetic, structural characteristics of colloids produced by ultrashort pulsed laser ablation a solid Fe target were studied four different media: HPLC water, an aqueous solution trisodium citrate, acetone, ethanol. Optical extinction spectroscopy revealed absorption band UV region for all, contrast results obtained with nanosecond...

This paper develops a parametric method for determining the core radius and shell thickness in small silver–silver-oxide core–shell nanoparticles (Nps) based on single particle optical extinction spectroscopy. The is study of relationship between plasmon peak wavelength, full width at half maximum (FWHM) contrast spectra as function thickness. reveals that wavelength strongly dependent thickness, whereas FWHM depend both variables. These characteristics may be used establishing an easy fast...

The study of metal nanoparticles (NPs) is great interest due to their ability enhance optical fields on the nanometric scale, which makes them interesting for various applications in several science and technology. In particular, properties depend dielectric function metal, its size, shape surrounding environment.

This work determines the size dependent metal nanoparticle (NP) dielectric function from a 'top-down' approach using bulk experimental refractive index as starting point. Free-electron damping constant () and plasma frequency parameters in Drude model are calculated for nickel (Ni), molybdenum (Mo), tungsten (W), lead (Pb), zinc (Zn) sodium (Na) method developed our group. Determined allow to develop an expression that improves precision reproducing discrete wide wavelength range (UV-FIR)....

Copper metal nanoparticles (Nps) have received increasing interest during the last years due to their potential applications in several fields of science and technology. Their optical properties depend on characteristics dielectric function metal, size, type environment. The contribution free bound electrons copper Nps is analyzed as well influence its plasmonic properties. corrected for particle size under 10 nm, introducing a term inversely proportional particle's radius damping constant....

An analysis of the diffracted beams emerging from three-dimensional photonic crystals is herein presented. The wave vectors nonspecular are calculated for a triangular two-dimensional lattice and change in their directions as function wavelength confirmed experimentally case face-centered-cubic colloidal illuminated under normal incidence. A fluctuating behavior beam intensity incident light predicted perfectly ordered lattices. As it specularly reflected ballistically transmitted beams,...

Studies of fragmentation process gold nanoparticles (Nps) in deionized water after generation by femtosecond laser ablation were performed. To analyze the process, direct IR ultrafast pulses or super-continuum (SC) radiation focused colloidal solution used separate steps. and SC generated externally a sapphire crystal directly inside applied under low fluence regime. In latter cases, to evaluate effect on different spectral bands present SC, we have determined efficiency regions...

Silver nanoparticles (Ag NPs) colloids obtained by femtosecond laser ablation in soluble starch (st) solution and silver salt reduction methods were characterized using optical extinction spectroscopy, micro-Raman transmission electron microscopy, zeta potential. Type, number density, relative percentage of species determined for the first time based on OES Raman analysis. Both synthesis yield bare Ag core–shell Ag@Ag2O spherical NPs with log-normal size distributions centered range 1–3 nm....

This paper is devoted to determine an analytical expression for the thickness dependent complex dielectric function case of Ag and Au thin films. Free bound electron contributions are dealt with independently. Using Drude model former taking experimental refractive index values films, we apply a previously developed method first time damping constant plasma frequency parameters specific film thicknesses. Fitting separately each one these allowed us find their dependence on arbitrary...

The perturbation produced by pulsed laser generated discharge in an electric field is studied as a tool for breakdown characterization. A focused high-power induces air or solid target, that placed between the plates of planar charged capacitor. induced generates temporal redistribution electrical charges on can be easily measured resistor connected to ground plate. This signal depends energy used generate breakdown, capacitor applied voltage, and distance plates. In this work, we show...

Silver metal nanoparticles (Nps) are extensively used in different areas of research and technology due to their interesting optical, thermal electric properties, especially for bare core core-shell nanostructures with sizes smaller than 10 nm. Since these properties size-dependent, size measurement is important manipulating potential functionalization applications. Bare coated small silver Nps fabricated by physical chemical methods present specific characteristics extinction spectra that...

There is a continuing need for measuring nanometric film thicknesses wide variety of industrial and scientific purposes. Kretschmann-type sensors are well-known multilayer sensing devices. This work focused on two objectives: firstly, the design an Ag2O Kretschmann sensor and, secondly, development measurement protocol determining silver oxide thickness when given initial gradually converted into by exposure to controlled oxygen-rich atmosphere.