Laser Ablation Of Copper Target Research Articles

Effects of energy and hydrogen peroxide concentration on structural and optical properties of CuO nanosheets prepared by pulsed laser ablation

Laser ablation of copper targets using Ce:Nd:YAG laser with pulses of 1064 nm wavelengths at 10 ns pulse width and with different laser pulse energies and in different concentrations of H2O2 solution is investigated experimentally. Cu/CuO flake-like nanostructures with visible band gap and the extension of its light absorption by changing the synthesis parameters such as laser pulse energy and concentration of H2O2 solution were observed.Characterization and comparison of the obtained suspensions are exploited by X-ray diffraction (XRD), UV–vis spectroscopy and field emission scanning electron microscopy (FE-SEM). The XRD analysis data show that in 10 vol% H2O2 solution CuO phase has been synthesized, while with decreasing the H2O2 concentration, Cu phase is also observed. The mean crystallite sizes of CuO were estimated using XRD patterns and were between 2.1 and 3.3 nm. The comparison of the UV–visible absorption spectra indicates that with decreasing pulse energy and decreasing H2O2 concentration up to 5 vol% the band gap of nanoparticles increased from 2.19 eV to 2.34 eV, which is accordant with the quantum confinement effect. FESEM image of all the synthesized samples illustrate the formation of flake-like nanostructure with the thickness of about 12–15 nm.

Copper Oxide NPs: Synthesis and their Anti-Dermatophyte Activity against Trichophyton rubrum

Trichophyton rubrum (T.rubrum) is a pathogenic dermatophyte that can causes fungal infection in keratinized layer of the human tissues such as skin, hair and nails. This work was carried out to study the antifungal activity of CuO nanoparticles (CuO NPs) on the viability of T.rubrum. CuO NPs have been synthesized by pulsed laser ablation of copper target immersed in liquid media using Q-switched pulsed Nd:YAG laser with 1064 nm. The optical properties and the surface charge of CuO NPs colloidal were characterized using UV–Vis spectrophotometer and Zeta potential techniques. UV–Vis spectrophotometer exhibited two peaks of absorption of CuO NPs colloidal: sharp peak at 200 nm and another peak at 630 nm. Zeta potential technique showed negative charge of CuO NPs colloidal (-28.16 mV). The morphological properties of CuO NPs such as particle size, shape and particle size distribution were characterized using Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM), the shapes were spherical and the particle size distribution was inhomogeneous which ranges between 20 to 180 nm. The synthesized CuO NPs presented suitable fungistatic activity against T.rubrum and its highest growth-inhibitory effectiveness was at high concentration (100 μg/ml) and high exposure time (3 hrs). Moreover, the inhibition rate of T. rubrum progressively increased with increasing CuO NPs concentration and exposure time.

Neutral atomic jet generation by laser ablation of copper targets.

This work aimed the obtainment of a neutral atomic jet departing from a plume generated by laser ablation of copper targets. A pair of electrodes together with a transducer pressure sensor was used to study the ablated plume charge composition and also to measure the ion extraction from the plasma plume. The neutral beam was produced with this setup and the relative abundance of neutrals in the plasma was measured, it decreases from 30% to 8% when the laser fluence is varied from 20 J/cm(2) to 32 J/cm(2). The necessary voltage to completely remove the ions from the plume varied from 10 V to 230 V in the same fluence range. TOF analysis resulted in center of mass velocities between 3.4 and 4.6 km/s, longitudinal temperature in the range from 1 × 10(4) K to 2.4 × 10(4) K and a Mach number of M = 2.36, calculated using purely hydrodynamic expansion approximation.

Laser ablated copper plasmas in liquid and gas ambient

The dynamics of copper ablated plasma plumes generated using laser ablation of copper targets in both liquid (de-ionized water) and gas (air) ambients is reported. Using time and space resolved visible emission spectroscopy (450-650 nm), the plasma plumes parameters are investigated. The electron density (ne) determined using Stark broadening of the Cu I (3d104d1 2D3/2-3d104p1 2P3/2 at 521.8 nm) line is estimated and compared for both plasma plumes. The electron temperature (Te) was estimated using the relative line emission intensities of the neutral copper transitions. Field emission scanning electron microscopy and energy dispersive x-ray spectral analysis of the ablated copper surface indicated abundance of spherical nanoparticles in liquid while those in air are amalgamates of irregular shapes. The nanoparticles suspended in the confining liquid form aggregates and exhibit a surface plasmon resonance at ∼590 nm.

Ion dynamics in ultrafast laser ablation of copper target

We investigate the angular distribution and average kinetic energy of ions produced during ultrafast laser ablation (ULA) of a copper target in high vacuum. Laser produced plasma (LPP) is induced by irradiating the target with Ti:Sapphire laser pulses of ～50 fs and 800 nm at an angle of incidence of 45o. An ion probe is moved along a circular path around the ablation spot, thereby allowing characterization of the time-of-flight (TOF) of ions at different angles relative to the normal target. The angular distribution of the ion flux is well-described by an adiabatic and isentropic expansion model of a plume produced by solid-target laser ablation (LA). The angular width of the ion flux becomes narrower with increasing laser fluence. Moreover, the ion average kinetic energy is forward-peaked and shows a stronger dependence on the laser pulse fluence than on the ion flux. Such results can be ascribed to space charge effects that occur during the early stages of LPP formation.

Fabrication of cuprous oxide nanoparticles by laser ablation in PVP aqueous solution

The cuprous oxide nanoparticles have been fabricated through pulsed laser ablation of copper target in PVP aqueous solution. The structure, morphology and composition of the nanoparticles have been characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray photoelectron spectroscopy (XPS) and X-ray excited auger spectra (XAES). The results show that the mean size of the as-prepared in diameter is about 29 nm with a relative narrow size distribution and samples are polycrystal Cu2O nanoparticles with a shell of thin layer of amorphous CuO. Furthermore, a possible mechanism for formation of such the cuprous oxide nanoparticles is discussed. We concluded that pulsed laser ablation of copper in liquid is a feasible method for the synthesis of cuprous oxide nanoparticles.

Kinetic energy distribution of ions in the laser ablation of copper targets

In this work we report on a study of the plasmas produced in laser ablation of copper targets by XeF ( λ=351 nm) excimer laser irradiation. The kinetic energy of positive ions was measured by energy resolved time of flight mass spectrometry. Average kinetic energies of the Cu + ions of the order of 1–30 eV were observed, as a function of the laser pulse fluence. The experimental kinetic energy distributions show a double-peak structure. The first located at very low kinetic energy (∼1 eV) can be related to a thermoionic component, whereas the second is strongly dependent on laser fluence.